Previous methods of light-controlled adhesion require either (1) specially designed custom polymers, (2) ultraviolet irradiation, or (3) chemically modified glass surfaces. Light controlled adhesion that bypasses either 1-3 above may be desirable.
De-adhesion may be useful during the semiconductor manufacturing process. During this process polymers are adhered to inorganic surfaces like silica and it may be desirable to develop a polymer with the ability to de-adhere during the microfabrication process.
Researchers at UCR have developed a new additive that may be added to adhesives. When the UCR compound additive and polymer adhesive are exposed to visible light, this significantly weakens the adhesive bond. The additive and adhesive may be mixed at room temperature and then it may be applied to surfaces to adhere them together. Upon exposure to light the surfaces de-adhere.
Fig. a shows solid dye particles encapsulated between 2 glass slides which are glued together by the UCR additive incorporated into a polystyrene film. 532 nm irradiation causes the polystyrene adhesion to fail and the bottom slide to drop off in Fig. b, releasing the red dye into the surrounding water.