High-Speed and Stepping MEMS Rotary Actuator for Multimodal, 360° Side-Viewing Endoscopic Probes

This paper reports, for the first time, a MEMS rotary actuator that enables side-viewing microendoscopic probes with different modalities for luminal tissue analysis. The developed tubular-form micro rotary actuator offers both high-speed and stepping motions that are compatible with the use for optical coherence tomography (OCT) and Raman spectroscopy, respectively. The actuator, improved from its preceding designs, shows up to 125× higher revolution speeds per power while enabling arbitrary angle-resolved stepping rotations in a ∼50% thinner body, with significantly reduced heating effect for biologically safe operation in vivo. Preliminary testing of the OCT endoscopic probe integrated with the developed rotary actuator/scanner successfully demonstrates real-time 360° imaging of live human skin tissue.