Multiple-pattern generating piezoelectric fiber scanner toward endoscopic applications

We present a mode-optimized two-dimensional piezoelectric fiber actuator and a robust actuation scheme to establish three different scan patterns with the same device. Having multiple scan options, the operator of the actuator is free to choose between improved uniformity, high frame rate to image abrupt biological event, or circular field-of-view to better image cylindrical cavities (gastrointestinal tract, esophagus, etc.) that are cylindrical in nature. We demonstrate the capabilities of the device, through first presenting its mechanical frequency behavior, then offering an actuation scheme to achieve different scan patterns, and finally generating 256 pixel width or diameter raster, spiral, and Lissajous patterns at ≥20 frames per second. With further development, the presented actuator design and drive scheme could serve as a useful tool as part of a minimally invasive optomedical device in the clinic.