Engineers and designers want ever-smaller focusing lens with ever-higher-pixel counts.
Edited by Stephen J. Mraz
And of course, they want it all for a lower price, especially for handheld devices like camera phones. Many portable devices currently use fixedlens systems because focusing systems add too much expense. This leads to many out-of-focus images. To get around these problems, engineers at Philips Research in the Netherlands (www.research.philips.com), are developing liquid lenses that precisely curve water to change focal length and magnification. They shape the water using an electric field, a phenomenon called electrowetting.
The lens they have made can zoom, is immune to shocks, consumes little electric power, and is temperature tolerant, thanks to salt or antifreeze added to the water. Putting a small expansion vessel on the device lets the liquid expand and contract with temperature. The researchers are confident that as portable devices get smaller or applications need smaller lenses, the technology can be scaled down to at least the MEMS range and be made using micromachining with vapor deposition and etching.