This story has been making the circuit, but this Register article is the first that I’ve seen which has any real detail. As part of my interest in telescope design, I’ve developed a passing interest in camera lens design, and I was uncertain just how this would work.
Basically the idea is that two different liquids are held inside a conical chamber, usually an oil in the back and water in the front. A charge is applied differentially between the front and the back with the result that as an increasing charge is applied, the oil layer in the back goes from flat to highly convex. Interesting.
Camera lens design is basically a balancing act to control seven or so primary aberrations that can affect final image quality. This lens assembly would seem to be able to control only one degree of freedom (roughly speaking, power of the element: when the charge is off, the assembly is a simple window, when the charge is on, it acts as a lens with some power and significant chromatic aberration). It seems to me that any successful attempt to use such an element in a camera design will likely require more than one of these elements, particularly in a zoom configuration.
Still, very interesting work. I’ll have to do a patent search to see if I can find some real designs based upon this principle.
Addendum: Apparently Phillips has been persuing similar work, and disputes the patents granted to Varioptic for this design. It will be interesting to see how that plays out, possibly in the court system.