Electromagnetic omnidirectional scanning micromirror with multi jet fusion printed structures for smart factory applications

This paper presents a new omnidirectional scanning micromirror fabricated with a multi jet fusion three-dimensional (3D) printing process. The proposed electromagnetically actuated wobbling scanner has an aluminum-coated 6 mm-diameter mirror supported by quadpod springs and magnets for actuation. The analytic model for optimizing the driving coil is presented and compared with the finite element analysis results. The core part of the structural layer is fabricated by the 3D printing process and assembled with a separately fabricated reflective surface, permanent magnets, and coils. Three different combinations of magnets are tested to improve the optical scan angle of the device and provide a wider field of view (FOV). The one-dimensional (1D) horizontal (H) scan angle of 15.2° is obtained at 415 Hz, and 14.5° is obtained at the vertical (V) scan mode at 406 Hz. The applied current at both scan modes is less than 100 mA_rms. The two-dimensional (2D) scan capability is also analyzed by generating the Lissajous, circular, and spiral scan patterns. For the spiral scan, a 2D FOV of 8° is achieved with the driving frequency of 400 Hz and the phase difference of 120°, which is equivalent to the FOV of 360° × 4°, the vertical angular resolution of 0.01°, and frame rate of 1 fps for light detection and ranging (LiDAR) system optics. The amplitude modulation depth and frequency are 100% and 1 Hz, respectively. The developed device can potentially be utilized in various LiDAR applications for the smart factory.