Polymeric (SU-8) optical microscanner driven by electrostatic actuation

A torsional micromechanical scanner was fabricated using photosensitive polymer (SU-8). The proposed polymer-based optical microscanner with reduced torsional stiffness offers a new approach to increase scanning angles. The scanner consists of two parts; the top layer (micro mirror and electrodes) and the bottom layer (anchors and electrodes). The SU-8 scanner is actuated by electrostatic force generated by gap-closing electrodes. For the fabricated optical scanner with the mirror size of 3 × 3 mm2, the experimentally obtained scanning angles were 0.43° for 60 Hz (non-resonant) and 1.54° for 1.13 kHz (resonant) at the input voltage of 160 V. This paper also proposes a simple and new fabrication method, which can effectively control the stiffness of the torsional springs by molding SU-8 photoresist through V-groove on the silicon substrate, thereby increasing the scanning angles.