Leti MEMS Workshop to be held in Barcelona, Spain on June 18, 2013 has a presentation on Wavelens - the recent Leti spin-off working on MEMS-based AF. The idea behind the new startup is shown on Leti slide and described in Feb. 2013 issue of I-Micronews newspaper:
"Wavelens’ optical MEMS consist of an optical membrane released onto an optical oil-ﬁlled cavity, with MEMS actuators embedded at the membrane periphery. As an operating principle, when the MEMS are actuated, the optical oil flows through the membrane center—modifying the membrane’s curvature and introducing a focal length variation. These patented optical MEMS are fully compatible with classical MEMS actuation technology—only a few microns displacement is required. Thanks to the optical oil, the voltage required is typically below 10V, because of the low force needed to change the membrane curvature, and the power efﬁciency is very high — consumption is below 0.1mW. The optical MEMS outline is also very competitive with classical X and Y dimensions of 4.5mm, an overall thickness below 500μm, and an active thickness of only 50μm.
...One of the key advantages provided by these optical MEMS is that working at low voltage results in high efficiency. ...Another advantage is that these optical MEMS are also flexible and can be adapted to speciﬁc requirements in terms of the optical aperture (up to 5mm in diameter) and wavelength range (in the visible spectrum and other wavelengths). ...While Wavelens’ optical MEMS are particularly adapted to autofocus and zoom applications, they can also be used for optical image stabilization."