High-Temperature-Resistant Polymer-Based 3-D-Printed Electromagnetic Scanning Micromirror

In this letter, we present an electromagnetic scanning micromirror fabricated using 3-D printing with a high-temperature-resistant polymer. The micromirror comprises a 1-D scanning mechanism featuring a large gold-coated silicon mirror, supported by a 3-D-printed structural layer consisting of a mirror holder, gimbal, and two sets of torsion springs. The design incorpora- tes a series-connected dual spring-mass-damper system to enhance the optical scan angle at resonance. Actuation is achieved via Lorentz force applied to a self-supported coil inserted into the gimbal. The reflective surface has roun- ded edges and an outer dimension of 4.2 × 15 mm². Permanent magnets are assembled with an aluminum jig on either side of the mirror holder, with a minimal gap of 0.55 mm. The device is fabri- cated using three different 3-D printing methods (digital light processing (DLP), fused deposition modeling, and stereolithography) and four different materials and subsequently tested. Among the fabricated devices, the one printed via DLP 3-D printing achieved a maximum optical scan angle of 20° at 1248 Hz, with an input current of 110 mA_rms. Various characteristics of the 3-D-printed and assembled devices, including dimensional accuracy, surface topography, temperature effects, and driving characteristics, were analyzed. The fabricated micromirror can be integrated into a 2-D scanning module for light detection and ranging systems.