Engineer and ex-Special Forces officer Brett Bagwell spent eight years redesigning the U.S. Army’s riflescope so that it uses less power, thus extending the battery life, and is lighter and more accurate. Most importantly, it lets shooters zoom from low to high magnification at the push of a button. The scope, called the “rapid adaptive zoom for assault rifles” (Razar), lets soldiers shift magnification without taking their hands off the rifle or eyes off the target, a problem with the current scope.
The focusing subsystem changes the focal length of two or more lenses by varying the curvature of the lenses’ surface. The lenses do not move as they do in traditional optical-zoom devices. Razar consists of a polymer lens core with two flexible, hermetically sealed membranes encapsulating a polymeric fluid. A low-power piezoelectric actuator adjusts the curvature of the polymer lens, zeroing in on the correct position within 250 msec and to an accuracy of 100 nm.
The device could also find use in medical imaging, binoculars for everyone from soldiers to birdwatchers, and cell-phone cameras where the optical zoom would eliminate the pixilated images associated with digital zoom.