The electrowetting liquid lens offers several key features that are unmatched by other actuators:
- Large range of optical variation
Displacing a liquid interface allows large phase shift variations: more than 200 waves in a typical Arctic lens, where liquid crystals or other adaptive systems are limited to about 10 waves. When used in focus variations, that means for instance 40 diopters (10 times the eye accommodation) over a 3mm diameter aperture.
Liquid lenses have been tested for over 100 millions cycles without any performance degradation, while mechanical systems such as piezo, motors and VCM (Voice Coil Motors) are typically limited to a few hundred thousand cycles.
- Shock resistance
Under drop test, the liquid lens behaves much better than mechanical solutions like VCM. Repeatability of LL response curve is excellent before and after shock tests. In a VCM system the lens is suspended to a soft spring, resulting in offset positions changes after every shock, causing increasingly degraded focus performances.
Liquid reconfiguration can be as fast as tens of milliseconds. These time scales are well adapted to human interfaces, video, photo capture etc…
- Low power consumption
Liquid lenses will typically dissipate about 15mW, driver included, which is about 10 times lower than VCM, piezos or motors.