Liquid Lens ...!

Camera phones will soon have lenses made from nothing more substantial that a couple of drops of oil and water, but will still be capable of auto focusing, and even zooming in on subjects, says Etienne Paillard, CEO of French start-up Varioptic.

Of course, folks like myself who are keen photographers are going to pipe up with scorn saying nothing new! Sure, Nikon introduced this technology in their cameras way back in 1979; but, it was a closely-guarded secret then and nobody was quite sure what precisely the lens did. All we knew (and were ecstatic about) was that it took the best pictures in the world!

Varioptic was founded two years ago to exploit two core technology patents covering lenses based on the principles of electro-wetting. This is the tendency of liquid to spread on a substrate, Paillard explains. "It means we can tune the shape of the drop to create a lens. Think about a tunable lens, like in the human eye".

The lens has a simple structure: two liquids, of equal density, sandwiched between two windows in a conical vessel. One liquid is water, which is conductive. The other, oil, acts as a lid, allowing the engineers to work with a fixed volume of water, and provides a measure of stability for the optical axis. The interface between the oil and water will change shape depending on the voltage applied across the conical structure. At 0V, the surface is flat, but at 40V, the surface of the oil is highly convex.

There are several advantages to having a lens built like this; no moving parts so less to break and more rugged. Power consumption is very low; 10% of a motorised auto focus lens. It also has the potential to be made very small. Presently, the limit is a few millimetres, but research is on to shrink the lens further. Varioptics is developing the lens for use in endoscopy as well as camera phones. They have a non-exclusive deal with a Samsung-subsidiary to develop the lenses for camera phones and products will be on shelves by Q1 of 2006 or maybe even in time for Christmas 2005. The first product will be the auto focussing lens, but in a year's time Varioptics will have a true zoom capability, using two liquid lenses.