Design of a Low-Cost Resonant Electromagnetic Scanning Mirror and its Drive/Sense Circuitry

This paper presents the novel design and fabrication of a scanning micro-mirror for LiDAR applications, with particular emphasis on its performance, cost-effectiveness, and materials used. Various scanning mirror prototypes, each featuring a scanning mirror plate of 10 mm by 10 mm, were fabricated using different materials: 0.3 mm thick FR4 and polyimide substrates. Different electromagnetic coil structures were eval-uated to optimize the scanning performance. The performance attained by each prototype is compared and discussed. The paper also delves into the design of the electromagnetic actuation and sensing circuitry of the mirror. Voltage and current sensing of the actuation coil is implemented with the aim of achieving sensorless positional control. The scanning mirror was designed to have a low resonant frequency in the range of 250 Hz to 550 Hz. An optical angle amplitude of 24.1° was achieved for the micro-mirror design using the 0.3 mm thick polyimide substrate.