However, a radical change in the technology will allow for even faster auto-focus acquisition times. The technology is called MEMS, short for microelectromechanical technology and differs drastically from the current voice coil motors (VCMs) used in smartphone cameras. It is the same technology that brought us microphone, gyros and barometers in a tiny smartphone. It is extremely precise - made in clean rooms just like all other chips - and is hundreds of times more power efficient.
Voice coil motors are the current technology and they employ technologies that are a bit dated now. Auto-focusing in VCMs happens when a current is sent through a coil causing the moving elements of a camera to move in the direction of a magnet. There are a few set steps for the moving elements and at each one the camera evaluates the focus to determine whether the image is in focus or not (if not it just moves one step further and re-evaluates). It sounds complicated because it is. Plus, with that many steps locking focus could take a whole second. It is also imprecise and noisy.
MEMS technology on the other hand can focus nearly 7 times faster and is much smaller. It uses electrostatic force to draw to solid-state comb-shaped surfaces together, but they never touch and degradation takes much longer. Instead of having multiple moving elements you only have one with extremely quick auto-focus and power consumption of 1mW, hundreds of times less than VCM modules.
Companies developing MEMS cameras include Tessera and DigitalOptics, and the latter showed an extremely slim, 5.1mm 8-megapixel “mems|cam” camera module at MWC. It is ready to ship to Chinese smartphone makers. At a price of $25 apiece though it is nearly 25% more expensive than camera modules used in devices like the Galaxy S4. To get a clear understanding of the benefits of having the MEMS system, take a look at a demonstration of the camera at MWC right below.