Wide-angle structured light with a scanning MEMS mirror in liquid

Microelectromechanical (MEMS) mirrors have extended vision capabilities onto small, low-power platforms. However, the field-of-view (FOV) of these MEMS mirrors is usually less than 90° and any increase in the MEMS mirror scanning angle has design and fabrication trade-offs in terms of power, size, speed and stability. Therefore, we need techniques to increase the scanning range while still maintaining a small form factor. In this paper we exploit our recent breakthrough that has enabled the immersion of MEMS mirrors in liquid. While allowing the MEMS to move, the liquid additionally provides a "Snell's window" effect and enables an enlarged FOV (≈ 150°). We present an optimized MEMS mirror design and use it to demonstrate applications in extreme wide-angle structured light.