Lens-size drops

A technique for creating a liquid lens from two droplets of water could make a new generation of low-cost, lightweight, energy-efficient cameras a reality.

Researchers at Rensselaer Polytechnic Institute designed and tested the adaptive liquid lens that can capture 250 pictures per second and requires considerably less energy to operate than competing technologies.

The lens is made up of a pair of water droplets, which vibrate back and forth upon exposure to a high-frequency sound, which in turn changes the focus of the lens.

By using imaging software to automatically capture in-focus frames and discard any out-of-focus frames, the researchers can create streaming images from lightweight, low-cost, high-fidelity miniature cameras.

'The lens is easy to manipulate, with very little energy, and it’s almost always in focus - no matter how close or far away it is from an object,' said project leader Amir H. Hirsa, professor and associate department head for graduate studies in the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer.