Fixed Focus: Adjustable lenses from liquid droplets
By Peter Weiss
Grinding glass is one way to make a lens. Using plastic goop, a little salt, and electricity is now another way. That’s what researchers at Lucent Technologies’ Bell Labs in Murray Hill, N.J., have done to create lenses the size of sesame seeds.
The lenses are even adjustable. The salt added to the goop, a liquid-polymer precursor, makes it electrically conductive, so the lenses’ shapes can be adjusted by applying voltages. Once the droplet assumes the desired form, a few minutes under an ultraviolet lamp polymerizes the liquid into a hard lens.