Abstract
A tunable-focus liquid lens, composed of liquids is a kind of optical devices. The lens consists of two immiscible liquids and the liquid-liquid interface is formed. Unlike the working principle of mechanical zoom lens, the focal length of liquid lens can be tuned by dielectric force. Dielectric force is induced by the difference of dielectric constants between the two immiscible liquids. That the interface deforms and causes a lensing effect is breakthrough of the optical lens. Liquid lens must satisfy many requirement of physical and optical properties for the two immiscible liquids, for example, density, refractive index, viscosity, dielectric constant, surface tension, transparency, boiling and freezing point. Besides, liquid lens had its market, especially consumer electronic products. Therefore, passing thermal test including storing temperature test (S.T.T)and thermal cycling test(T.C.T) is a necessary condition for liquid lens. After thermal test, the liquid combination becomes opaque and has a low light transparency. This phenomenon is called emulsion, a dispersed system between the oil and water phase and makes the lensing effect fail. Therefore, understanding the mechanism of emulsion and trying to solve it are my research key point.