Design and Fabrication of a Tunable Two-fluid Micro-lens Device with a Large Deflection Polymer Actuator

Abstract

A large deflection polymer bending actuator was employed in the design of an integrated micro-lens with electrically adjustable focal length. This micro-lens consisted of micro-fluidic chambers bonded together and sealed by an elastomeric lens membrane to which the polymer actuator has been attached. For focal length optimization, the chambers could be filled with fluids of different refractive indices. The multilayered actuator of radial shape and the variable micro-lens chip design were optimized using 2D FEM simulations. Fabrication steps included bonding of polymer actuator stack with the elastomeric lens membrane on a micro-machined silicon wafer. For a tunable micro-lens with 3mm aperture, a tuning range in optical power between 0 and more than 15 dpt was achieved.