Welcome back to this course on nanostructured materials, synthesis, properties, self assembly and applications. So, we are in module 3 and in the last lecture which was the first lecture of module 3 and today we will be doing the second lecture of self assembly of module 3 which is actually the lecture number 8. So, the lecture 7, 8 and 9 of module 3 correspond to the lectures of self assembly in nanostructured materials and in the first lecture of self assembly which was lecture 7 of module 3, we discussed what is self assembly, how it can be brought about and we started with some applications. Today, we will continue on the self assembly of nanostructures which is the second lecture and the lecture number 8 of module 3. Now, the systems of interest for self assembly, why are we interested in self assembly? There are lot of examples in the natural or life sciences in bio systems. For example, you have self replicating and self repairing systems. Self replicating means that they can produce objects which are similar to them and self repairing means if some part of the molecule or a biopolymer gets affected then it can recreate that part by itself. You have nano muscles, nano mechanical devices where you require the concepts of self assembly then there are systems in biological cases where nano ports and nano channels are involved, vesicles, capsules, motors, actuators they all are important in bio systems and concepts of self assembly comes in many of these cases. Further, we can build a micron scale assemblies from nano scale constructs and then you have soft assembly of hard nano structures. The soft assembly like low temperature and shape selective roots to dots, nanotubes, viscose and asymmetric shapes of carbon based materials. There can be semiconductors and they can be metals. So, hard nano structures means something say a carbon material or cadmium sulphide, cadmium selenide which are semiconductors. These are we are calling them hard nano structures and we are calling it soft assembly because we are using a solution route using molecules or a simple nano materials to make self assembled structures which ultimately yield these hard nano structures. So, hard nano structures typically is something which is inorganic mostly either a metal or a semiconductor or an insulator. It can be an oxide, a nitride, a chalcogenide or simple carbon based material. So, these hard nano structures made by soft methods, soft methods mean without going using high temperatures or without using any plasma or laser for the assembly of these nano structures. We refer them as soft assembly using low temperature or room temperature methodology using solution growth roots. If we can generate oxides or other metals etcetera is what we call soft assembly of hard nano structures. Then similarly, we can make templated assembly of two and three dimensional arrays instead of making particles or spheres or rods of these oxide nano structures or metal nano structures which we are calling as hard nano structures. We can make two dimensional or three dimensional array of these nano particles which now we refer to as two and three d arrays of hard nano structures using templated assembly of these molecules or molecular systems using a soft chemical approach. And these two and three dimensional arrays of nano structures are useful for applications because they are used for devices. And this is a methodology by which we do device fabrication on templates using a soft assembly or a self assembly process. We can also generate meta stable structures using this soft assembly of hard nano structures. Then systems of interest for self assembly what all systems are of interest was for example, in surfaces and interfaces we can control the electron transport by controlling the self assembly. Then we can control the solute surface interactions on the surfaces. We can make nano porous membranes with designed size and distribution of the pores which will also then control the surface area because if you control the size and number of these pores will control the surface area of these membranes which is important for several applications. Then these systems are of importance in nano lithography where self assembly is very important. Nano lithography means making structures in the nano dimensions based on some technique like here we are discussing self assembly. But you can also make nano lithography using electron beams, iron beams and lasers etcetera. Now here we are saying that using self assembly also we can do nano lithography which will be called soft lithography. Then you are interested in self assembly for various electrochemical and optical sensors and self assembly also leads to structures which are platforms for hierarchical organization of bio structures and cells. So, from the small simplest DNA and RNA etcetera how you can get to cells and then organelles and the whole system. So, self assembly is used as a platform for this kind of organization of bio structures and other cells. Now in the absence of templates or interfaces or external fields how do you get to have self assembly? Now for that you need a balance between attractive forces and repulsive forces. So, if you have both attractive forces and repulsive forces in the system and they can balance each other then you generate a molecular self assembly or a self assemble structure which is stabilized by this balance of forces. Now what are these different forces? The attractive forces can come through simple covalent bonding or hydrogen bonding or electrostatic attraction between oppositely charged ligands and depletion forces or dipole-dipole interactions. These all one or more of these will give you the attractive forces present in a system which is undergoing self assembly and that self assembly will be possible if the magnitude of the attractive forces is exactly balanced by repulsive forces. The repulsive forces are of two kinds one is the steric force which means that if you have bulky substituents around each other then those bulky substituents will have a steric hindrance and that gives rise to the steric force. The other thing is if you have similar charges so there will be electrostatic repulsion between those kind of ligands which are present and that will give rise to repulsive forces. So, two types of repulsive forces the steric forces and the electrostatic repulsion of like charges will balance one or more of these attractive forces and you will get a resultant structure at a distance which is optimized such that the attractive forces and the repulsive forces are balanced. Now, in the importance of self assembly in nanomaterials is immense there are many many applications for example, there is lot of use of optoelectronic devices. So, many many everyday gadgets and devices are based on optoelectronics. Optoelectronics is a branch of science and technology where you are combining optics or optical properties of materials with electronics. So, you see large displays monitors like large television screens or a plasma screens all of them have optical information and electronics involved with each other. So, there are many many sensors which are you can make using optoelectronic devices. So, the size of the optoelectronic devices is a matter of concern because you want to make smaller and smaller cell phones you want to make smaller and smaller laptops all of them depend on optoelectronics and. So, reduction on the size of these devices involve going to nano dimensions. So, self assembly in nanomaterials is one way which people are thinking or reducing the size of optoelectronic devices. Then there are other systems like plasmonic waveguides, light generators, focusing lenses, thermal switches, super hydrophobic surface, super hydrophobic means hydrophobic means something which dislikes aqua solutions or water. Super hydrophobic means a great disaffinity that means it really has a strong repulsive interaction with water or similar solutions. And this kind of super hydrophobic surfaces are of interest because if you coat them on surfaces then the surfaces will be clean you can wash them off easily with water. So, lot of applications are there of super hydrophobic windows, super hydrophobic walls etcetera. Then there are this is this large field of sensors all kinds of sensors they can be biochemical sensors, optical sensors, pressure sensors where you have importance of nanomaterials and self assembly of nanomaterials becomes part of that application. Now, coming to an example let me show you if you have nanoparticles. So, you have a large number of nanoparticles here and these nanoparticles can self organize or self assemble to form various kinds of structures. So, one of these structures is if they all align in a kind of a line it may not be exactly a straight line, but can be a curve. So, you have these particles which are disordered here under certain conditions they can align themselves to form chains. And this is a schematic diagram and this is a real picture taken under a transmission electron microscope where you can see these chains and there are many chains like these. And if you look closely at one of these chains then that will look like this. So, you will see 1 2 3 4 5 6 7 particles are here. So, it depends on the conditions that you have you can have 7 particles in a chain or 10 particles or 15 particles and here these are magnetic particles gamma iron oxide nanoparticles which have been coated with a mixture of nonic and 4 phenyl butyric ligands. So, these kind of particles coated with these kind of ligands are self assembling to form chains. This is another example where these particles are self assembling to form a sheet and this two dimensional structure which is a schematic diagram in reality looks like these. So, these are the sheets that you get and these sheets are observable under a transmission electron micrograph where transmission electron microscope and this is the micrograph where you can see these planar objects which are nothing but sheets and these sheets are can be explained to be made up of a two dimensional network of these original particles. And here in the inset you can see that this ordering is there is a perfect order because you can do what we call the electron diffraction of these material. If you do the electron diffraction you will see these lines which you can kind of index and each of these lines are correspond to certain reflection planes of these ordered structures. So, this ordered structure is made of particles of cadmium telluride. Cadmium telluride is a known semiconductor and here you have a self assembly of cadmium telluride nano crystals to form a 2 D sheet. This is a 3 D crystal. So, a three dimensional crystal where you have a more complex architecture and it is basically made up of gold nano particles. So, you can have different types of organization depending on the particles. The particles can be different kinds can be semiconductors can be metal particles and also on what you cap what you functionalize them and the conditions the P H etcetera will control the ultimate morphology or the self assembly of these particles whether you get a chain or whether you get sheets or three dimensional structures as shown in this case of a gold self assembled structure. Now, you can have template assisted self assembly of nano materials. For example, here you have a template the template here is for example, a some kind of a tobacco mosaic virus and you have gold particles which can be schematically shown here it can be a carbon nano tube or any other kind of rod. So, if you have a iron oxide rod whether you can have this kind of self assembly. So, these particles form a structure on top of the rod. So, then the initial rod is the template on which the self assembly is taking place. So, this is a real picture a transmission electron micrograph of gold nano particles are the small spheres you can see are on this rod which is a virus and this virus is a particular virus which is called the wild type tobacco mosaic virus and on top of the virus you have got these gold nano particles. So, you have self assembled the gold particles on the tobacco mosaic virus this is another example where you can see there is a carbon nano tube it is a light gray structure which you can see and you can see there is a gap at the center and that is that is hollow. So, this is a carbon nano tube which is hollow and on top of the carbon nano tube these rod shaped objects are gold nano rods. So, the gold nano rods have taken the shape of the carbon nano tube. So, this is a template assisted self assembly of gold nano rods and the template in this case is a carbon nano tube. This is another example where you are having a self assembly of barium chromate nano particles. So, you have several barium chromate nano particles this is a schematic diagram. So, if this is one barium chromate nano crystal and this is another nano crystal of the same material the two come together in the presence of some molecules which are shown here and these molecules are called surfactants and these surfactants basically act as if they have two types of charges they have or two types of properties they have a hydrophilic head group and a hydrophobic chain and this is typical of most soap molecules where you have a hydrophilic head and a hydrophobic chain. Now, when you try to bring these two close together then the hydrophobic tails interact with each other because you know like attracts like and so both of them are hydrophobic that means they hate being in a aqueous environment and so both of them have the same nature they are both hydrophobic. So, they come together and when they come together they bring these two crystals together and so it is like you are stitching these two crystals through this surfactant molecules and then this can happen between the next two etcetera. So, in the presence of surfactant if you synthesize barium chromate nanoparticles you get this kind of array of particles this is self assembled because between two particles you have this kind of interactions which bring the two cubes together. Now, this kind of a rectangular super lattice can occur in some cases depending on conditions you may have more one dimensional organization. So, here the arrangement is along this direction only. So, it is not forming a 2 D lattice like this super lattice where you have interaction along this axis as well as along this axis here you have interaction only along one axis. So, you get a chain of nanoparticles or nanocrystals of barium chromate and so these are surfactant these are examples of surfactant induced self assembly of barium chromate and nanocrystals and depending on the surfactant you can change them into a 2 D layers or one dimensional chain like structures the self assembly is caused by surfactants. Now, this is another example here you can program the assembly by doing some intricate chemistry. So, you have to design some molecules which you want to tag on to gold nanoparticles. So, you have gold nanoparticles and you design a molecule using these kind of base pairs. So, here T stands for thiamine A stands for adenine and C stands for cytosine and G stands for guanine. So, you can make a chain of base pairs like this and on this side of the thiamine you have a thiol group attached. Now, this thiol group you know thiol groups prefer gold particles. So, wherever they will find a gold particle this thiol group will get attached to the gold particle. So, this oligomer of bases through the thiol group gets attached to this gold particle and so it gets modified and those are the A what is written is basically gold particle modified by this oligomer of bases and it has the 5 prime free because on the 3 prime side is the thiol and that thiol gets bound to the surface of the of the A particle. Similarly, you may have another gold particle another solution of gold particles which we call B and which is functionalized or modified by a different sequence of base pairs. So, here was a different sequence this is different sequence and when this attaches to the gold particles using again the thiol group you get a different gold particle because you have a different oligomer on the surface and this we call B. So, when you mix A and B both A and B have these base pairs and you know that thiamine will always attach to adenine. So, thiamine of this will attach to adenine of this like that they too will come together and they will form then you add a DNA duplex. So, you have this A particles modified by this and you have this B particles modified functionalized by this and you have them in solution and then you add a DNA duplex which has on one end one stranded DNA and another end another strand of DNA and this part of the DNA will attach to the A particles because the A has this functionality where thiamine will attach to the adenine of this and adenine of this will attach to thiamine of this. So, this part of this linking molecule will attach to the A particles and this part of the linking DNA will attach to the B particles and once they are attached this side to B and this side to A basically A and B will come together. So, you will now have complexes of A and B and still some functionalities will be free to bind. When those bindings occur you will have further oligomerization and you will get a ordered structure. So, this is called programmed assembly because you have planned exactly how this should assemble by functionalizing with a very specific chain of bases and having another particle with another specific chain of bases. When you bring them together in the presence of this kind of DNA you will have only a particular kind of arrangement which will settle down to give you this kind of ordered structure. So, this is a programmed assembly now the same thing what we were discussing of the programmed assembly this is what happens. So, assume that your A is a large gold particle and B is a small gold particle then the large gold particle with its functionalization and the small gold particle with its functionalization are brought together and then you have the linking DNA strand the linking DNA strand is basically this one. So, that is the linking DNA strand and when you bring them then these two particles join together. So, the large particle and the small particle join together and then this small particle can join to another one and then this one can join to another one and this is the real pictures that you see. So, you can see this kind of agglomerates and you can see large particle with small particles around and in this picture it is a T a micrographs where you can clearly see a large particle with small gold particles and in between them is the linker molecule and that can be seen in between those two particles. So, this small particles are self assembled around this large particle and that can be seen clearly these are several of these large particles with small particles around them and if you zoom on to one of these particles then you see this. So, DNA strands have been used for programming the self assembly for assembling. So, it may be better called programmed assembly rather than self assembly because you have made the molecules in a manner in a particular fashion. So, you have programmed that the molecules will come together only in that fashion and that you are successful the T e m is proof of that that you are successful in doing that and you have those particular small particles small gold nanoparticles around the large nanoparticle. Now, this is another example of programmed assembly where again you are using thiol to link on to gold surfaces. So, because it is now well known that thiol can attach to gold surfaces. So, to thiol the S H group you can link an alkyl chain now. So, these are alkyl chains which is a schematic diagram the alkyl chain is shown here many alkyl chains are there and this blue dots are the thiol at the end of each alkyl chain. Now, suppose you bring them close to a gold surface through a kind of a orifice or through a hole in a tube. So, this typically can be of the order of half a micron or so. So, 500 nanometers or even less may be 30 40 nanometers. So, you will have all these chains coming down when they come down on the surface since it is gold particles are there the gold will align with the thiol and. So, the thiol will be on the close to the surface. So, all the blue dots you see will be at the bottom touching the gold surface and the alkyl chains will be pointing at upwards. Now, if I move this. So, I move my capillary or my pen which is normally this is called dip pen lithography you can do it using a kind of a tip which is called an AFM tip or type of AFM tip which moves in a particular fashion wherever it moves it brings these molecules into assembly with the gold surface and you get a pattern of molecules.  So, this is a programmed assembly and that is this is a schematic diagram to help you understand and this is a real picture where you can see that something has been written with molecules and this is over dimension of 70 nanometers and this is the thickness is around 15 nanometers. So, basically this thickness is 15 nanometers. So, whatever this orifice diameter is 15 nanometers probably close to that and that is why you can get this kind of lines. Now, you can make many kind of patterns depending on whatever shape geometry you want and this patterns is not only for making designs there has to be some application based on these patterns. So, you make a particular pattern a design because you want to make an application of this. So, maybe you will connect this with some wires or you will connect it with some other tubes which has a specific application right now what you have got is a particular pattern that you wanted of a particular molecule and then you have to put this patterned surface into application into use mostly very much useful is in the biosensing applications where this kind of patterns are very important. Now, another example of a programmed assembly is you have again a designer molecule you synthesize this molecule which is diamino pyridine and this diamino pyridine is linked to the silver here the particle is silver again through a thiol group and. So, you have this silver nanoparticle with thiol linked to this particular molecule which is called diamino pyridine and you have another linker molecule which is called diuracil and this diuracil has got this kind of moiety O nitrogen O. Now, this type of moiety immediately finds this kind of nitrogen So, you have this kind of a pyridine ring here and it forms hydrogen bonds. So, one end of this diuracil molecule immediately binds to this part of the diamino pyridine molecule when it binds on to this side the other side which is free finds another molecule like that and it binds to that molecule from the other side. So, this is like a linker with two hands one hand holding this silver ion silver atom and the other hand holding this silver nanoparticle. So, both sides you have silver nanoparticles which are functionalized using thiol groups and then having this pendant molecules which can bond through hydrogen bonding to this linker molecule which is diuracil. So, the effect is that you bring the silver particles together. So, this kind this can continue you can have a molecule on this side also you can have a molecule on this side also and. So, if you look under the transmission electron micro graph that the where there are lots of these kind of silver nanoparticles with linker molecules you will get a large number of this kind of silver particles self assembled because of your choice of molecules and. So, it is been programmed to assemble in a particular fashion and you can see these assembled structures. This is a schematic diagram of these silver particles with this kind of a hook attaching to this. So, these two molecules have been shown with this kind of pictures schematically to make you understand how these silver particles are coming together through these linker molecules. So, this is another case of programmed assembly. Now, you can have what is called field directed self assembly field directed can be electric field or magnetic field or some other kind of field, but mainly electric field and magnetic field which have reasonable kind of forces can generate forces can generate forces for this kind of self assembly. Now, you have iron oxide particles which are magnetic and you want to assemble them into chains. Now, if you take simple iron oxide particles. So, these are simple iron oxide particles and these particles if you apply a magnetic field where B is a magnetic field and you are applying the magnetic field in this direction. So, what happens these iron oxide particles will align in the form of a chain. Then if you remove the magnetic field that means you switch off the magnetic field that means you take away the magnet if it is a permanent magnet or you switch off the current of the electromagnetic. So, there is no magnetic field then this chain will get disturbed and it will go back to a disordered structure. So, from a disordered structure you got a linear chain like structure and then you will get again a disordered structure if you remove the magnetic field. Now, if you want to permanently have that structure then you have to lock the particles. So, what you do you have a polymer on the on top of the particles when you have the polymer on top of the particles and you apply a field it gets aligned when you remove the field the particles are still aligned and then if you want to disturb this alignment you change the pH or temperature and then the particles will be disaligned. But if you remove the field the particles are still aligned. So, the chains remain intact after the field has been removed when you have this kind of a polymer brush on top of it which basically interlock between themselves. So, this polymer can interact with the polymer of the other particle and form a kind of a can join together which you cannot remove even if you remove the magnetic field. But you can disturb this if you change the pH. So, this is a field directed self assembly with locking nano particles. Now, you can have other kind of what are the different techniques by which you can have self assembly in colloidal particles. Now, that is of two kinds one is the convective assembly the other is the capillary assembly and the interactions that happen during this convective and capillary assembly are due to several forces and these forces are magnetic forces electrostatic forces sedimentation confinement. That means, you are forcing the particles close together and host guest interactions. So, all this some one or more of these forces will be involved in a colloidal system when you bring about assembly through convective mechanisms or through capillary forces. So, this is convective assembly where you have a flat surface and you have particles in a solvent. Now, the solvent flow which is called the convective flow along with the particles is driven by the evaporation of the solvent. So, suppose you have a temperature gradient that means, whenever the liquid with the solvent with the particles is coming here the solvent is evaporating. When the solvent is evaporating the particles are getting aligned on top of the surface and since the solvent is evaporating more of the liquid or the solvent is coming in this direction. So, the solvent process starts when the thickness of the solvent layer becomes equal to the particle diameter right. When you have more solvent such that the thickness is more than the diameter then the assembly is still not taking place only when the diameter of this particle becomes nearly equal to the solvent thickness then the assembly occurs. Now, this is mainly being driven by convective flow and the convective flow is because solvent is evaporating. So, there is a drive to come on to this side. Now, there can also be capillary forces which occur when the top of the particles are extending from the solvent layer and that can lead to extended layers or multi layers. Basically capillary forces are between the wall and the liquid or between two particles when they have some liquid then you can have capillary forces. So, the combination of convective assembly in patterned surface this is a this surface is not patterned. In this case the surface is patterned. So, somewhere you see you have some protrusion and somewhere there is a depth. So, particles are sticking into these depths and that can happen due to combined effects of convective flow and attractive capillary forces because the top of the particles may protrude from the solvent layer. Now, the mechanism of convective assembly is simple that you are basically dragging a liquid layer along this plane. So, you have a surface and on the surface this film is forming and the liquid this is the contact line where the solution is confined and you are moving this and then that convective transport of the particles take place and it gets ordered at the line of contact. So, here already the film has formed the particles have formed an ordered array and on this side it is still a liquid and as it moves you can order the particles. So, convective flow carries the suspended particles towards the contact line and the confinement effect induced by the meniscus coupled to the capillary forces when the particles are drying that leads to the formation of the two dimensional lattice. So, the convective and capillary assembly of particles can be seen here and then these are basically the microscope to visualize this and this is if you want to measure the contact angle you can measure the contact angle and this is a motorized stage this is how you move the stage and this is a motor attached to it and there are heat exchangers to vary the temperature along this surface. So, you can that is a mechanism of convective assembly and this is the real picture this was a schematic diagram of the film formation of the ordered self-assembled layer and this is a real picture and this shows that this part has dried this is the drying region and you can still see some particles there and these particles will move towards this side as there are there are these terms which are the rate of evaporation which is given J evap and there is the J I that is the movement towards this interior or towards the contact line. So, how these factors the growth velocity of the layer is dependent on several factors like the rate of evaporation over the drying length. So, this is the drying length and so it is proportional to that then it depends on porosity it depends on volume fraction of the particles in the suspension that means the concentration of the particles it depends directly on that and then there are other factors the height of the assembled layer etcetera. So, this equation gives you the growth velocity of the layer how fast you can grow the layer on this surface and so there are several of these terms which tell you about this growth velocity. Now, if you want to control the thickness and the structure. So, here you can control the substrate velocity the particle volume fraction and the solvent evaporation rate all these you can control by controlling the temperature. So, the temperature of the substrate whenever it is greater than temperature of the dew point you will not have the evaporation. So, when the temperature of then you will have the evaporation whenever the substrate temperature is high then you will have the evaporation and you will have the monolayer formation. Suppose the substrate temperature is low then the dew point then you will have the reverse you will have condensation and not of the solvent you will not have evaporation. So, in this case when you have the substrate temperature much larger than the dew point temperature you will have evaporation and because of convective flow the particles will align and form the self assembled structure. So, you will get monolayer formation. So, these are monolayer which is being formed and the particles are coming rushing towards the contact line whereas, if the temperatures are same then it stops further assembly and no further movement is there and when the temperature of the substrate is low then you start having condensation that means the solvent comes back and whatever layer was formed this layer starts breaking up and these nano particles start getting into solution. So, you see whatever film was formed now the film is again started breaking and you have particles movement in this side towards the solvent direction. Here when the layer was forming the particles were coming towards the layer. So, the particles were coming towards the contact line from the particle in reach in the solvent it was coming towards the contact line and would eventually form layer. When the temperature of the substrate is much less than the dew point the layer which had formed has started breaking and the nano particles start moving into the solvent. So, by controlling that temperature you can control this evaporation and the condensation and hence you can control the self assembly you can also control using the substrate velocity the particle volume fraction etcetera. The particle volume fraction is basically the concentration of the particles if you vary that also you can control the coating thickness and the structure of this mono layers. Now, this is a picture the earlier this was a schematic diagram explaining how the mono layer formation is taking place or how the mono layer was breaking and this is a real picture where this is a FEACM picture where you can see that you have a layer and if you look closely you can see the nano particles arranged in the layer and this is at a much closer scale this is some 200 nanometer scale and this is 2 micron scale. So, you can see it on 200 nanometer these are approximately 100 nanometer sized gold particles which are on a PDMS which is poly dimethyl siloxane a very common polymer and on top of that you have got these gold particles which are arranged so nicely so beautifully it is using convective assembly. Now, this if you take this is a top view if you take the side view or the cross section then you can see that this is made up of only one layer this is the substrate on top there is only one layer of these spheres of gold particles whereas, on this you can see there are two layers. So, if you take a cross sectional picture along the side you can see the number of layers which form on this substrate of PDMS. So, this is mono layer and this is bi layer of particles and these are of course, different particles the particles here a basically are gold particles whereas, the this C and D are of polystyrene particles made on PDMS as a substrate. Now, you can have capillary assembly this was previously we were discussing convective assembly this is convective assembly, but you can also have capillary assembly normally in capillary assembly you will not have deposition on flat surfaces because you need this angle which we call theta receding angle is should be less than 20 degrees for the capillary assembly to take place. So, on a plain surface this assembly this angle as you see is normally higher than that whereas, if you have a pattern substrate. So, this you can see is a pattern substrate and if you zoom in to this region you can see the step kind of thing and in this step there you it is possible to deposit particles on this step by capillary forces and this kind of assembly is called capillary assembly and it is possible to deposit only few particles in this kind of process it is not possible to deposit large number of particles using the capillary assembly for that you have to use the convective assembly. So, in this case you have a combined effect of the geometrical confinement because you are confining these particles within this geometry. So, you have these structures that you have made. So, there is a confinement effect and as well as capillary action the capillary forces are acting and you are getting this assembly. So, now during capillary assembly there can be an influence of the temperature and this is shown here. Suppose the substrate temperature this is you are having a substrate which has a particular geometry it is not planar and hence it can help in capillary assembly. Now, in this case this is when the substrate temperature is less than a particular critical temperature then evaporation does not compensate for the recirculation flow. So, there is a flow which is given by J. So, J R is the recirculation flow and if you do not have the substrate temperature high suppose it is low then the evaporation does not compensate for the recirculation flow and you cannot have any particle deposition. However, if you have so this is the contact line this is the real picture and this is a schematic diagram. So, the since there is some evaporation, but it is not sufficient because the recirculation is pretty high and you do not have any patterning, but if the substrate temperature is high the evaporation rate is high and then you have this kind of a self assembly in these pattern substrate where the particles are getting collected and then you see this region where the at the contact region you have this self assembly of particles and that happens when the substrate temperature is much larger than a particular critical temperature and this large substrate temperature leads to high evaporation rate and when the high rate of evaporation is there then the J i which is the rate at which the particle is flowing towards the interface is much higher than the J R the J R is the recirculation rate. So, the incoming rate J i compensates for the J R and hence induces the action accumulation of the particles. So, this is the last slide today and this is what we show is another example of vertically aligned gold nano rods. So, you have got gold surface and on the gold surface is of course, on top of silica surface and silicon surface, but what is important is on gold surface if you put particles which have got on the surface thiol groups the thiol groups will attach on the gold surface and you will get a pattern like this. So, these are gold nano rods on top of which is thiol functionalized and when you drop these particles on a gold surface they stick on top of them and so they form an array and if you look closely at this array you will get this ordered structures of this thiol functionalized gold rods on top of the gold surface. So, here again you have self assembly a vertically aligned gold nano rod where both convective and capillary assembly technique is used. So, there is a gold surface and thiol capped gold nano rods are forming a pattern on top of the gold surface this is a low resolution picture is a high resolution picture of the gold particles capped with thiol on the gold surface. So, thank you very much and we will meet in the next lecture our final lecture on self assembly. Thank you.


Welcome folks, this is Tom O'Brien of TFNN. We have five days a week, we go seven hours a day, we go 24 hours a day on the internet at TFNN.com. Always remember folks, whatever you think about, you bring about whatever you focus on grows. Hope everyone's having a great day, safe day. It's making a great night, folks. Create new agreements based on respect and love. Take the responsibility to make new agreements with those you love. And if agreement doesn't work, change the agreement, create a new one. Use your imagination to explore all the possibilities. Mug and wise, let's take a look at it out here. We have the Dow Industries down 34, Nasdaq up 70, S&Ps off two and a half. Gold, gold contract up $51.70 trading in 2018 and ounce. We have silver up 38 cents, $23.17 an ounce. Light Sweet Crew down a buck 50, trading at $69.41 a barrel, notes and bonds. Ten-year note, up a full point plus two ticks at 1605, the 30-year, up 31 ticks at 13130 and King Dollar. King Dollar trading up 127 ticks at 102, 475. The euro is out here at a price point of 108. The yen is at a price point of 130 and the British pound is at 122 to one US dollar. Our phone number is<PHONE_NUMBER>. It was a call folks, wanna know what's going on in your world and the world of the S&Ps. Let's take a look at about you. This is just as good as you can get folks, okay? When I just did the update, you know, the S&Ps, you gotta see this man. I mean, this is about as great as you can get and when you're trading. Bottom line is as doing the update, the S&Ps were down at that 39.50. It pops up to 39.93. So you popped 40 S&P points and you gave up another, let's see, 90, we gave up another 15 just as quick. Bottom line, this is a market that wants lower price and I expect it's gonna get lower price. They just reloaded. That's all they did right there is reload and let's just take a look at this. I'm curious as they hit the 382. It went over the 382 to the 50. You know, bottom line, the expansion contraction Fibonacci sequence folks, okay? Hits beyond belief in fast markets. Just does, I have no idea why it does, but guess what it does? Gold, let's go take a look at the gold contract out here. We take a look at gold. What do we have with gold out here? Gold is testing, it wants to test the highs that were generated out here a couple days ago. So if we take a look at this, what you're gonna see in the gold market, you're coming up to the way over the, you're in a new range number one. You know, anything over 1,083 you're in the range, the high that it's going after right now is the 2,031. Right now, you're at 2,015. We go into the, I mean the currency market, this is what it's all about, man. The dollar is running things once again. Let's see, that's the dollar, and I'll get me get here. Okay, so the dollar rejected lower price and it was right back to where it came up the last time. It added strength, the low when it came off that low was 1,015,46. Today we hit 1,019,15 and then it took off and we're at 1,025,03. Now, what you have out here today, yelling once again, what that pop was about also by the way, that was about yellings, they just released yellings testimony that's going on this afternoon and she's back again saying, here's a deletion, let's see, okay. Okay, so here it is. As I, this is what's deleted from yesterday. As I said last week, the US banking system is sound, the federal government recent actions have demonstrated that the resolute commitment to trade the necessary, to take the necessary steps to ensure that deposits save and remain safe. The new paragraph is that as I've said, we have used important tools to act quickly to prevent contagion and they are tools we could use again, the strong actions we have taken to ensure that American deposits are safe and certainly we are prepared to take additional actions. Now, let me show you this, man, you gotta see this. Let me pull this over, I wanna thank Jacob for putting this together for me, so where do you see this? Now, this is going to be the new deal, folks. And what this is, this chart, if you can see this chart, I've laid this chart over the, maybe I can make it even bigger. Yeah, I can, okay. So this chart here, they're worried about the regionals and they better be worried about the regionals because now this is a JPMorgan chart that came out with this, okay? But this is like so insane, it's unbelievable. When you're looking at this line, this is commercial real estate, this is lending and commercial real estate. Now the difference, this is what a difference is.  You have the First Republic, bad trade, they're in municipals, right? See this, the blue line? The blue line is lending to commercial real estate loans. Now the bottom line is that things have changed so dramatically since COVID that this is a huge problem. The blue line is the amount of loans that were done by regionals, okay? This is what's that, that's in the trillions by the way, okay? The large banks, look at the large banks down at the very bottom. The large banks, man, are not there. This is gonna be, no, not going to be, this is the problem. This is the problem that the Fed knows, the Treasury knows. These loans here are into water, man. There's no way they're not, they're into water. That is the canary in the coal mine. So this thing is just starting. It's not over, it's not even close to being over. Our phone number is<PHONE_NUMBER>. We take a look at some of the higher volume equities out here, and what do we have? We have Block, Block got hit by Hindenburg out here today. That's down 11 and a half dollars. You have First Republic, that's down 67 cents. NVIDIA's up 485. You got Coinbase, they got hit by the SEC. That's down 11 dollars. Inside the NDX100, the Stripe versus the weakness inside of the NDX, what do we have out here?  Taken away from it. PayPal down three, Dollar Store down two and a half, Serious Satellite down 2.3, and Marriot off 2.3. Inside the Dow Industries. We're talking about a spread inside the Dow Industries. This is pretty about as tense as you can get. Dow Industries out here, we had a high today of 32,511, a low of 31,866. How's that for a spread? Point wise out here, what do you have? Microsoft putting 29 positive points, Amgen 13 taking away from it. United Health 46, Travelers 18. Stay right there folks, we'll come right back.


Hey everyone and welcome to this session on the trends and DevSecOps and cloud development. You've got a few too, who would I like to say developers, myself or wise, a developer and security practitioner in background and now founder and CEO at Urban IO and with me one of my favorite people is Philip or Dev Advocate. Philip, you want to add a few words about yourself? Yeah, sure. So I mean, I'm a developer advocate, but I do have a background in engineering. I used to lead a team at Cisco, the front end efforts especially at Cisco. Cisco is a networking company and it involves a lot of security. So I'm sure I'll be able to have some input as well, some interesting input when we come and talk about DevSecOps and cloud development this year and maybe the possible trends of next year. Awesome. Yeah, I'm kind of excited for this. It's always good to kind of sum up a year and trying to take a glimpse in what's coming forward and I think through this year we've seen a lot of interesting things both with just our own work and the work we do with our customers and you especially were really at the front line engaging with people, helping them build things. So I'm really excited to hear what how you summed it up and so maybe that's a good place to start. Just what are the highlights that you've seen working this year in both the DevSecOps space and in general in cloud development? Yeah, I think a lot of people, I mean, actually software is becoming very prominent in everyone's lives, not even just the companies that are tech related, but also just normal people that need to use tech these days. And there is a big trend and a big prominence on actually having security be part of those trends and be part of those ever-growing companies that are involved in tech. Just to kind of take a few steps back, I think it's an interesting contrast how a few years ago we didn't treat security as like a very, very big priority, at least not as high of a priority as it is right now. And what we noticed is, for example, take it back like 10 years, nobody really cared about authentication, even more so about authorization. I don't think that was a concept much back then or at least a talking point. And everyone built their homebrew solution. Everyone did everything on their own. And then move forward the few years until today, authentication is almost becoming a standard with every company. No developer wants to work on it because there's companies that do it better. And same thing with kind of authorization, I think it's becoming almost a thing that is a requirement. Security is growing ever higher. And people just don't want to do the hard work and they're moving and trying to find solutions that they can incorporate in a simple way to save them time and to add value to the company. So I think that's kind of a big thing that we saw this year and it's going to grow even more into next year. I definitely agree. I think software is eating the world. It's kind of a common understanding now everyone's realizing it. But we see it like also with shift left, really more and more elements are moving to the developer side, more and more elements of both security operations. Everyone wants to start them as early as possible. People are starting to realize that if you try to add that later, it doesn't really work well. And then it's also a question I think that's what you kind of touched on the question of what are the baseline and what are the fundamentals you're building on? How much are you trying to invent yourself and how much you're adopting as an existing best practice or tool that you can use? And I think maybe another very interesting angle on that is that this is affecting a lot more people. So it's not just developers. We're seeing product managers, we're seeing sales, we're seeing professional services, we're seeing the security people also from the other angle. Everyone's kind of honing in on the DevSecOps angle. Everyone wants to be able to chime in and how you do security on the development cycle itself, how you bake in security into the product in the earliest stages. And it's more funny to see like with product managers that not necessarily the most technical people, but they have to be now. They have to understand what it's like to be a developer, and they have to understand how security works, because they have to have those baselines as part of a product. You can go without authentication today. And as you said, as opposed to 10 years ago, no one wants to build it from scratch. Authentication is a proven thing now. Just like it used to be like 10 years ago, we added our understanding of think with encryption already. You don't want to roll your own. No understanding has already kind of taken another step forward with authentication. You don't want to roll your own. And I think we're starting to see that authorization as well. In general, maybe everything that isn't a core part of your product and especially if it's not a core part and it has a ability to affect the stability or security of your product, it's better off to use at least an open source solution or at least the best practices that the market has come up with instead of trying to do it on your own. And I think it's interesting to see, especially with the type of customers that we're seeing. So one of the things that really surprised me this year is the amount of healthcare companies, either companies that are actual healthcare providers or ones providing services to healthcare providers or around healthcare or Medicare. So I was surprised to see how many of those are moving the fastest with adopting the new best practices with adopting policies code, adopting authorization as a service or permission service. So as someone who's really at the front lines, can you maybe share, how did you engage with those customers? What are the things that they're asking? I mean, I think just taking one step back as well, just to highlight the point on, having people like product managers have to be part of software now. I think what we're seeing is that in general, security is very difficult. It's a very difficult concept that requires a lot of knowledge to grasp, especially for developers. It requires a huge amount of knowledge to implement. And it's hard to implement security within an app. There's too many things that you need to make sure that are working and no developer wants to be put in a situation where they write a piece of code and it doesn't work or it doesn't work the way it should. And then there's some security flaws in the system. That's probably a developer's worst nightmare. So I think what we're seeing now is a big chef shift to software that's very easy to use, very abstract. And that's where we talk about no code UI. And now going back to client meetings, I think a lot of the companies that we spoke to, companies that are in healthcare, in security, they have this whole team of developers that are willing to build this. But they don't want to build it themselves. They want to use something that's already out there. And that's not just to make it easier for the developers, but it's also to allow other team members to be able to use the product and have an understanding of the product. So this is kind of what we're seeing with our clients. More clients are actually coming to us and they're asking us about the solution that might be offered. And they're very interested in seeing how they can do it in an abstract way where they can engage the rest of the team. Right. So it's not just about the developers getting the security tools. It's about the developers enabling all the other folks to work on those tools as well. I think that actually puts us in a very interesting junction between two trends. So one trend that is very apparent and kind of talked about is the shift left and kind of security becoming ingrained and everyone becoming a developer to some degree, everyone working on on security, becoming something that is unavoidable for basically all the personas, all the stakeholders within a company. And another trend is the growth of code and specifically policy is code to manage all of these complexities. And there's, there's some, some of the attention there.  Everything is code is basically the hottest trend right now. But code is not accessible yet to everyone. Product managers might be a little tech savvy, but they're not full blown developers. The security people themselves that need to work with this, they're not full blown developers, at least not most of them, but they need to work on this. So on one hand, we want to manage things as code. On the other hand, we want to enable everyone to work on this. And these seem to be apparently in conflict. I have some ideas on where this is going to be. The thing one thing that you mentioned is through kind of low code. So interfaces that make it easier for not full blown developers to work on these problems and maybe even generate code for them. So no code interfaces that generate code I think are a swell thing that in the end of the day, you get that baseline and best practice of policy is code or configurations code. You manage it in a Git repository. You can do code reviews on it. You can do tests. You can do benchmarks. But you can have people at the top line generate that code without necessarily fully understanding it. In general, the low code, no code space is going very quickly. No code aspects are becoming a key part of almost every product. So just having that additional code generation thing I think would really become very valuable there. And I think that also touches on the number trend that we're seeing really exploding in these recent days. And that's generative AI. So machine learning component that you feed with some kind of low code interface. Maybe text prompts, maybe a form that you feel maybe another kind of interface. But at the end of the day, dead AI can generate text, code, interfaces, documentation for you. So having low code interfaces that are then funneled into an AI that generates code, that sets in a Git repository, that the developers can then collaborate with that AI on, I think that's a very exciting space. And I don't really believe in AI is going to take over everything and all the developers be out of jobs or anything like that. The jobs will just change, be collaboration with that AI. Using that AI to generate for ourselves, enable other people to generate code. And then still think that lower level of code as code is still a good thing that we have a lot of best practices on and how to manage complexity on. So you have a single source that makes it easier. What do you think of that? Or what are our other trends that you were saying? I mean, I think it's nice to see the retrospective of what has been happening before. And I think the first site where we saw a no-code UI come into place was with website creation. And it started off with people and having to hire developers to build that. And then obviously, there came the whole kind of group of companies that designed this no-code UI for not just people with little technical skill. It was even designed for people with no technical skill to be able to produce that website for themselves and maintain it. And that was done to kind of reach a really big market and reach a really big audience. And I think most companies now, especially in developer security, because it's a really hard concept to grasp, not just for developers, but also they want to include the people that may not have a technical background into the whole space because of a bigger market, they're designing all these kind of tools. I think everything that we see in software now very much revolves around automation. It's anything that's complex and anything that can be automated and abstracted is done or ways are found to be done. Because it just kind of really gives a faster workflow for companies. It really makes it much more of an easier process. So I think, especially with like we saw for ourselves, we saw a lot of companies in healthcare and compliance. And I still wonder why there is such a big interest there. But I think it's because they have all these other compliance issues on top of them that they have to deal with. So because then at that point, it gets so difficult that they're looking for solutions to just ease the whole process. And that's kind of my opinion, maybe why we might be seeing this kind of trend with healthcare. But yeah. I think it's double-fold. I think one, the complexity itself makes more people want compliance. Because when a system is very complex, especially if you're a security practitioner who is not highly technical, you're looking at another vendor and it's essentially another attack service. It's another risk that you are taking on if you're starting to work with them. But on the other hand, you don't want to do it yourself. You need that vendor, need that other player to take some of the burden off of you. But then you need that vendor to work for you in a way that you can trust. And the best way that we have so far, which I don't think is that good, but it's better than nothing, kind of like democracy. It's the best option of all the rest that we've tried, is compliance. So having the vendor meet the specific standard that you know is audited, that you know is standardized, that you know can be verified, can really help you as you engage in growing what you need to do when you're a product or in your company. And as more companies look at compliance as a way to standardize, engage with other vendors, also these vendors need to find a way to be compliant. And I think the spaces that have the most compliance pressure are healthcare, fintech, the security space itself, the government space. So that pressure on just we need to manage all of this complexity so we need compliance, forces a lot of companies to start with compliance that they want. And so they need to themselves adopt solutions to make the compliance easier. It's kind of a, I don't want to say vicious cycle, but it is a cycle. Like you need compliance, so you need better tools for the compliance, so you need better compliance for the tools, which need better tools and rinse and repeat. But I think in the end of the day, it's kind of a tide that floats all boats. The entire, the level of compliance that the standard that we think of, of what is the minimum compliance that a company should have is rising across the market. So I guess another, you can still start to be businesses today and you don't have to have certification that they want. But I think like in three years from now, five years from now, that will basically be nonexistent. And talking about better tools, how do you kind of see authorization as a service in that space? Because, you know, we see a huge amount of interest coming in from different companies in different genres of tech. So, you know, how do we see that kind of going forward? So I think with that, it's really, in the end of the day, if you look at compliance standards like SOC2, ISO, even the GDPR and CCPA, definitely things like HIPAA. In the end of the day, when you break it down, it's about 70 to 90% about access control. It's about how you decide within your processes or within the products you're building, who can do what and which scenarios. So a lot of times you can make the work of just having processes in place, having human readable policies that the humans in your organization have to follow. But it's a lot easier to make sure that people follow things if they're automatic guardrails. There are automatic checks that are more or better yet, automatic gates that control who can do what. And that applies both for what you're building internally and how your organization works, but also what you provide to your end customers. If you're building a product, in order for you to be compliant, you need to bake in access control and permissions into that product, both in how you operate it and how people use it. And your customers will have to have access controls. Everyone kind of thinks about RBAC as kind of the baseline. RBAC is kind of the role-based access control is the bread and butter of basically of compliance or permissions in any product that you build. So everyone today, engaging in products, knows to ask for RBAC. But I think that's just the beginning. The complexity is continuing to rise. The amount of people that need to be compliant is increasing because of that cycle that I mentioned before. And so I think it's getting to a point where having authentication, having identity management, having permissions as a baseline to start with anything you're building is kind of the easiest way to go. It removes a lot of friction from down the road because if you try to add it later, it will be more painful. And I think more and more people are realizing it just because of the basic demands that they're getting. If the demands are forwarded, just give me a product that works. Now it's give me a product that works and meet all of my standards, especially my security and compliance standards. But I think in this case, there is a lot of companies that are going to have the dilemma. And it's like, do I use this now or do I use this later? And I think many small startups, I think it's either a good thing or a bad thing if they use it later because there already might be for the process. And obviously the most difficult part, especially when it comes to authorization is, like, can I implement this now? Have I not started too late? Is it possible for me to move everything? And for startups, that's still, I think, manageable. But then think about all the really big companies. And we're talking like big fintech companies or big healthcare, they've got their own homebrew solution. It's very hard to scale. They're getting more people. It takes up so much time for the developers to be able to manage this solution. And here the decision comes, like, do they move? Do they stick with what they have? Is it worth it? Is it worth the time? Like, do you have an opinion about that? Do you think do you have a best practice of maybe what people should adhere to, like a top two tips or something like that? Yeah, that's a very good question. And I would say that even like within permit, that's something that, for example, with Asaf, my co-founder and our CTO, I discuss these kind of dilemmas on at least a monthly basis, I'd say. There's always this tension between having higher quality and having a higher velocity. You always have to choose. You can't have both. So it's about finding the right equilibrium point for you with each movement in time. And as every product, every company, every problem space is a snowflake. I don't think there's a silver bullet answer, like a panacea, that this is the right balance point for everyone. But I think recognizing that there is a balance point and kind of enabling you to move on that spectrum is really the way to go. And I definitely don't think, like I'd want to say as a vendor, everyone has to have a authorization as a service that they want. I'd like to say that, but I don't actually believe in that. I think what you want to have is the amount of access control that you need at each point. And you should invest in the minimum that you have. But be aware that it's going to change. Be aware of the more requirements around compliance or on security of both features. Access control, for example, is really about how people use the product. So that really translates into features that customers ask for. Give me invites, give me impersonation, give me approval flows, a lot of things like that. So those things are coming, if you like it or not. So it's about finding your equilibrium point, but planning to be able to transition into more things. And there I think best practices can really be helpful. Things like policy is code. To use policy as code doesn't cost you that much. It's just another way to define your access control. It doesn't add a lot of overhead. De-coupling your policy from your code. So having a separate microservice for authorization, even if it's just like a Lambda function that initially just returns through. It checks if it's your email, it returns true. If not, it returns false. Even that is better than having that same line of code embedded within the product itself. Because then if you want to upgrade, now the box ready, you can just pour more capabilities into it and upgrade it gradually. And in general, that's one of the best practices and trends that already saw its fruition and fruitation and growth in the cloud computing space. Microservices are, I don't think you have to break everything into a microservice, but using microservices to a certain degree, having some granularity, having to decouple your services is really a very smart best practice. If you plan to scale your software, and if you're building a business, you are planning to scale your software, microservices, at least to some degree, having a few microservices is the must. And then when you have that, you can try and identify the areas that are separate, that are not part of your core product. So classic things are like authentication, billing, analytics, permissions, databases. You can start with something that you ruin your own or start with an open source or start with a service in the cloud, but you want it separate. You don't want it locked in and coupled with your own code. So when new demands come in, you can switch in place and go. I think that's about it. So summarize microservices, decoupling your code, finding the right balance point for you at each point in time, and gradually adapting more services and tools so you can meet the standards, instead of constantly having to refact for your own code, which is very expensive. And I think with this situation, it kind of applies to any kind of developer tool product for a company to use is actually finding the problem within your own system and seeing if it can be improved. And I think quite often, it's hard to realize if that problem exists, or maybe it's hard to realize to take the first steps to actually do that. Now, of course, at permit, we would love for everyone to use authorization and to implement it as a full stack solution. But there are sometimes situations where, of course, you know, someone might find a homebrew solution more beneficial. Maybe there are some cases where, you know, it might be maybe not necessarily easier, but maybe more compliant or maybe something like that. Do you have any opinions about that? Like the mental load that you need is easier. Like, I know that if I'm writing the code, I can trust it because I trust myself. I don't know. I don't know. You seem like a nice guy, but I don't know. Can I trust you? That doesn't always work though. So it's, at least in the mental capacity, it's easier to start with smaller things that you do in your own. But it's important to remember that you probably don't want to stick with them throughout time. It's good for a while. There's a limit of how much you can build every little thing. In the end of the day, as a developer, as a product owner, there is your own specific unique product that you want to build into a shape with your energy on building other products that already exist. It's essentially reinventing the wheel. It is. Yeah, it is. And I mean, I think in general, when there is a solution, any solution for any company that can be, that a company can save time on, I think that's really beneficial in general. I think every time that you notice that there is a problem and you notice that you struggle with the problem and that there is no simple solution that you can find for it, that's usually the time when you should start thinking about outsourcing it to other companies who have spent and dedicated a whole team to making sure that the problem is understood, that the problem is solved, and that the problem is solved very well. So then later on, when the company grows and it scales, you don't have that issue coming up. Now, moving on, I'd like to just touch on and get your opinion about what do you think about just authorization growing in 2023? And so next year, what kind of things can we see pop up that maybe people are not expecting? And what would the generic kind of trends be? Is there any kind of differences that will be noticeable that we'll be able to see and maybe kind of jump on the wagon and use to make it better for any kind of company? Yeah, so maybe it's worth to kind of glance back at the short history of modern authorization. So this is a nascent space. It basically started to grow around 2020, maybe 2019, if you're really optimistic. Policy's code, this kind of grew solutions like open policy agent started to become more popular, especially with the growth of Kubernetes, and the infrastructure as code space or in general the infrastructure in the cloud space really pushed the growth of this space. And now it's starting to come into the application development itself. Up till now, I'd say most people, when you ask them how you go about building authorization, they'd say, what do you mean? I build it on your own. I just take in a few if conditions into my code, and that's it. I take a JSON web token, the more sophisticated ones. I take a JSON web token that I get from my authentication, and I push a lot of claims into that. And then I write code that parses all the claims in the JSON web token. And according to that, I'll have authorization within my product. And I think people are, as this space is growing and more people are becoming aware there's an alternative to building on your own, it will gradually become a standard. I think it's already at the cost of that point. And with that is also the maturity of the products themselves. Open Policy Agent is just one example, but more policy engines are out there. I think the most prominent new one that I want to mention is Cedar from AWS. So there's a policy engine that will soon be embedded into your AWS cloud service. And so this will really become the building blocks, policies, code, engines to parse them, services to have APIs for them, those within the next couple of months even I think would proliferate the space and become very commonplace. Then this question moves to how do people adopt this? And how do they maintain this and how do they work with this long-term? And there what I think we'll see is that people don't want to maintain this graph. People don't want to write policies as code. People don't want to build interfaces on top of them. They just want to be able to check off this thing so they can actually focus on building the products. I know personally, I found myself in my previous company at Brookup. They found myself rebuilding access control five times when the company wasn't even three years old. And I definitely didn't like that. I wanted to focus on that. Of course. And also the fact that I always thought, okay, this time I've built it. It's going to be perfect. Yeah. I don't want to talk about this graph again. And suddenly you get the use case that just froze you off completely because you just didn't think of it. And it's very hard to come up with all the points to make sure that you've covered everything, especially in security. So yeah. Yeah. So for example, we worked actually with Cisco as a vendor. And they came in and said, we want our own vendor, sorry, as a co-seller. And they said, we want our own back office. And I was like, I didn't think of going to the back office. And I had to go back to the drawing point. So having those, so mentioning the back office, in the end of the day, access control is about experiences. It's about interfaces that people can use. User management with the ability to assign roles, API key management, secrets management, audit logs. So the ability for you as a vendor to see what all of your customers did, all of the tenants did. And the ability for each of your tenants, each of your customers to see what they did on their own. The ability to ask permissions from another user, the ability to have an action that you're performing approved by another user. This list just goes on and on. And it's really classic things. And I think these things should be ready made.   This should be ready to bake in into your back office and to bake in into your product facing customers. So people won't have to deal with this. They don't have to think about reinventing this. They don't have to think about how to make this secure, how to make this work. So we're seeing a point where the infrastructure is getting really standardized. Policy is both getting more polyglot, but it's also getting standards and best practices that people can adopt. We're seeing APIs for this becoming very commonplace. I think the next thing is really the experiences, the interfaces. It was also becoming standardized. So when you come to an AI model or you come into a product, you will already know the interface that you're getting because it's the standard one. It has been customized for you, but it's a standard interface that allows you to work with complex policies and permissions, but the developer that built it didn't need to reinvent it and you as a user don't have to relearn it. That's really I think the next step in the permissions or authorization space. Yeah. I see a common trend and I think a lot of people when we're talking about security and when we're talking about authorization, they understand or at least the first people that even learn about authorization. They usually just understand it on the concept of admin and non-admin. But I don't think they have a concept of understanding how complex it gets. And you've mentioned so many things just now about API key management, just making sure that all of these examples are actually implemented and work, and then providing the experience for the user. And I've been a front-end developer, that's kind of what I really enjoy. And that's kind of what I like doing in my free time. And I know how important user experience is, especially when it comes to dealing with complex subjects. So I think we're an artist at heart. And I'm a creative artist at heart. I guess that's kind of true. And I can just see not only how much simpler it's going to make it, but how much the people are actually going to appreciate it. Because at the end of the day, it's about making things easy. You don't want to over complicate things. Nobody likes learning about complex stuff and then trying to apply it. Well, actually maybe some do, but that's... I think the difference is between working on learning and working on complex stuff that are at the core of what you want to do and having to deal with complex stuff that are just stopping you from actually building what you want. The stack is constantly becoming more bigger, wider, more scalable. So we need to specialize. You can't do everything all of the time. And then the focus shifts on what is your core? I think that's something that every developer, every company should ask themselves. What is our core? What do we do when we focus on and is unique to us that no other company is doing?  So you can focus on the things you should focus on. Exactly. Okay, cool. So I think I'd want to add a little bit from myself, just in general, what I think might happen with DevSecOps coming the next year. And I think, especially maybe focusing on the subject of our authorization, I think we're definitely going to see authorization evolve a lot. Like we've mentioned, we're definitely going to see kind of experiences come into place, experiences as part of DevSecOps, which I think is really interesting, because usually it was just very core stuff that hardcore developers were focusing on. But now we're actually getting to the stage where that abstraction, that no code UI will come into place, that management of all these really important topics will evolve and will become something that essentially becomes almost plug and play, which I think is great value to the whole developer community. I think there is going to be a whole increase in the kind of maybe other players in the market that do offer this kind of solution. But of course, I think it's quite an interesting thing that we see a lot of other companies do infrastructure level authorization, but very, very little do application level authorization. And it seems like infrastructure is very important, but also managing those permissions application level is very, very important too. So I'm curious to see if that focus kind of turns away or if it stays and how that's going to evolve later on. Yeah, for sure. So I think we've covered some good topics here. I think we had some recurring themes, both with low code, no code, both of shift left, kind of speeding up and bringing all the other stakeholders, not just developers into the mix. We touched on how compliance is speeding up through kind of a not a vicious cycle, but some kind of cycle. We touched on how low code, no code interfaces are going to power a lot of this, especially in the intersection with complex systems and machine learning models. We touched on how there's this tension between what you want to build and using policy as code for it, but enabling other people that are not necessarily code savvy to use policy as code and having code generating low code interfaces come into that way. We talked about what we see for our customers, specifically in companies in general in the space, we're seeing fintech and healthcare companies and security companies kind of lead the charge both with dealing with compliance and adopting these new solutions for better security baked into the products that they're working on. And we covered a lot of things, but I think these are like the main themes we touched on.  Absolutely. Everyone watching us also enjoyed this and maybe gained a few tips or insights or at least interesting trends to think about for looking back at the year that we had and looking at the upcoming year that we have. And I hope we all have a good compliance, secure and filled with great software year ahead of us. Absolutely. And I think in general, it's important to mention that we are very kind of open. We love chatting with others, especially about developer security. We're very easygoing. So we'd always recommend that you jump on and join our Slack and ask us anything about security. And we've got a whole team here that's really eager and passionate about the subject. So I would be most interested in engaging in the conversation and seeing what we can discuss and kind of the interesting topics we can cover. Yeah. People watching us, if you enjoy this conversation between Filipina and you'd like to have a similar conversation, just brainstorming ideas, talking about what you're building and getting our input on it or just brainstorming around security and cloud development. We love to do that. It's fun for us. The reason we do what we do is because we love engaging our developers and our security practitioners. If you can literally go on permit.io, there's a button to schedule a currently session with us to just pick a date and we show up. Yeah, that's exactly it. You don't even have to talk to us about permit, the product or about the open source project that can just talk to us about technology in general. We always enjoy that. So yeah, Filip, thank you very much. Thanks so much. Thanks for everyone watching and have a great year. Bye everyone.