Strength of adhesive contacts is determined by the work of adhesion which is also called relative surface energy of two contacting bodies. The relative surface energy can be determined by detaching of bodies of well defined shape made of one material from the substrate made from the second material. For example, the relative surface energy of the interface " acrylic glass – gelatin " is equal to 0.03 N/m. Experimental setup for measuring relative surface energy and its function can be seen in the video.