Dylan Knight Rogers
writes to tell us PhysicsWeb is reporting that US physicists have discovered a new liquid-crystal lens design
that can alter the focus by varying the voltage applied. From the article: "The new lens, which has been built by Shin-Tson Wu and colleagues at the University of Central Florida, allows the focus to be changed in a new way. The device consists of a mixture of liquid-crystal molecules and smaller N-vinylpyrrollidone monomers placed between two glass substrates, each of which is coated with a thin transparent layer of conducting indium tin oxide. They then placed a concave glass lens with a flat base on top of one of the substrates."