Based on mathematical models of the movement of fish, Maurizio Porfiri, engineering professor at Polytechnic Institute of NYU, built a robofish. When Porfiri let the robot go for a dip in the lab pool, the real fish started to mill about the robot and even follow it around. Watch the Science Friday video of the robots swimming.
IRA FLATOW, host: Time now for our Video Pick of the Week. Flora Lichtman is our multimedia editor - is here. And I'm looking on my paper, it says, robofish.</s>FLORA LICHTMAN: That's right, Ira.</s>IRA FLATOW, host: Robofish.</s>FLORA LICHTMAN: Robofish.</s>IRA FLATOW, host: Dun dun dun dun dun dun dun. Not a shark.</s>FLORA LICHTMAN: We're bringing "Jaws" in every week.</s>IRA FLATOW, host: Shark week, shark month on Science...</s>FLORA LICHTMAN: It's always shark week on Science Friday.</s>IRA FLATOW, host: Tell us about what robofish is.</s>FLORA LICHTMAN: Yeah, it's an unusual robot. It's a fish about the size of your hand, and it's designed, really designed to swim with the fishes. This is a robot that's made...</s>IRA FLATOW, host: That's a different movie. That's...</s>FLORA LICHTMAN: Yeah, right? So the designer is Maurizio Porfiri...</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: ...and he's an engineer at NYU Poly here in New York.</s>IRA FLATOW, host: Mm-hmm.</s>FLORA LICHTMAN: And he studies movement, basically, using math. And so he's looked at fish schooling and tried to understand how fish school by making these complex mathematical models. And then he takes those sophisticated models and tries to turn them into, you know, devices, objects.</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: So he made this little robotic fish. And here's the most amazing part of the story. So he makes this little robotic fish - and you can see it on the website, swimming around. And on his birthday, they stick it in the lab swimming pool, in the tank, and they put in some golden shiners. And this is just sort of for fun. And they noticed something kind of surprising happening, which was that when they put the robot in and turns it on - it's remote controlled - the little fish started sort of milling about the robot and they even followed it around the tank.</s>IRA FLATOW, host: Like its leader, like a school of fish following the robofish around.</s>FLORA LICHTMAN: Following the robo leader. Now, there's, you know...</s>IRA FLATOW, host: They didn't expect that?</s>FLORA LICHTMAN: They didn't really know...</s>IRA FLATOW, host: They just did it as a prank and they learned something...</s>FLORA LICHTMAN: I mean, I don't know if it was a prank or not. I mean...</s>IRA FLATOW, host: Yeah.</s>FLORA LICHTMAN: ...the idea is to build robots that are biomimetic...</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: ...that are like fish. But I think the - what's different about this research is that they build this biomimetic robot and then they put it back in with the biological system and saw what happened. And they're not biologists...</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: ...so they're not making any great claims...</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: ...that this is - they understand what makes a fish a leader.</s>IRA FLATOW, host: A bunch of engineers building a robot.</s>FLORA LICHTMAN: But they did say, well, you know, we did notice this sort of strange thing happening, which is that, you know, some percentage of the time the fish will follow it around.</s>IRA FLATOW, host: And you can see that. It's very fascinating. Go to our website at sciencefriday.com, our Video Pick of the Week up there in the left corner. And you can just click on this video, and there's a little fish coming - the robot, and the fish are following it around.</s>FLORA LICHTMAN: And then, you know...</s>IRA FLATOW, host: It's almost like they're imprinting on the robot.</s>FLORA LICHTMAN: It's a little creepy, I think...</s>IRA FLATOW, host: Yeah.</s>FLORA LICHTMAN: There's something sort of surprising about it. But I think what they're going to keep doing is building sort of different versions of this robot to try to understand what about it makes it attractive...</s>IRA FLATOW, host: Mm-hmm.</s>FLORA LICHTMAN: ...to the fish that they're working with.</s>IRA FLATOW, host: I guess they should bring some fishologists in or, you know...</s>FLORA LICHTMAN: Yeah. I think they have - eventually, the idea will be to collaborate.</s>IRA FLATOW, host: Right.</s>FLORA LICHTMAN: ...with people who know a lot about fish behavior.</s>IRA FLATOW, host: And do they have just one robot fish or...</s>FLORA LICHTMAN: No, they have several, actually.</s>IRA FLATOW, host: Yeah.</s>FLORA LICHTMAN: They just developed a new one, which is a little bit noisier. It can move faster. It's built for more challenging terrain than the lab swimming pool.</s>FLORA LICHTMAN: So the idea is that...</s>IRA FLATOW, host: Upstream, it's going to be...</s>FLORA LICHTMAN: Right - to take fish away from the dam. I mean, the idea is actually that maybe you could use robotic fish to lead fish away from dangers like...</s>IRA FLATOW, host: Mm-hmm.</s>FLORA LICHTMAN: ...an oil spill, for example.</s>IRA FLATOW, host: Or into the open net of a fisherman.</s>FLORA LICHTMAN: You know, they didn't mention that, but I - that's right. This could be a boon for fishing. It's sort of a remote control lure. Come to me.</s>IRA FLATOW, host: All right. Now, we've got the commercial side of this figured out. Thank you, Flora.</s>FLORA LICHTMAN: Thanks, Ira.</s>IRA FLATOW, host: Flora Lichtman, the Video Pick of the Week. It's robofish up there on our website at sciencefriday.com. It's great little video. And it's kind of interesting to see how these engineers came up with this fish that actually acts more like a fish than they thought it would.