Using sound to manipulate low-cost liquid lenses could improve the small cameras built into mobile phones, say US researchers.
Demand for high-performance cameras – and hence lenses – in consumer gadgets like cellphones is still growing.
Liquid lenses, composed of a single droplet of water, are tipped to become more popular with manufacturers because surface tension makes the drops almost perfectly spherical – something hard to achieve cheaply with hard materials.
Earlier this year liquid lenses made by Varioptic, in Lyon, France, appeared in a cheap webcam. In this device, an electric current curves the boundary between oil and water into a lens that focuses light.
But Amir Hirsa at the Rensselaer Polytechnic Institute in Troy, New York, points out that the Varioptic lens and other existing liquid lens technologies must use brute force to overcome surface tension and refocus a liquid lens.
