A micromachined water-immersible scanning mirror using BoPET hinges

Publication date: Available online 19 August 2019Source: Sensors and Actuators A: PhysicalAuthor(s): Song Xu, Shuangliang Li, Jun ZouAbstractThis paper reports a new micromachined two-axis water-immersible scanning mirror using BoPET (biaxially-oriented polyethylene terephthalate) hinges. A new fabrication process based on deep plasma etching on a hybrid silicon-BoPET substrate was developed to enable high-resolution patterning and batch fabrication capability. For demonstration, a prototype scanning mirror was designed, fabricated and tested. It has an overall size of 5 × 5 × 5 mm3, which is comparable to that of a typical silicon-based micro scanning mirror. With a short-hinge design, the size of the mirror plate reaches 4 × 4 mm2 to provide an even larger aperture for optical or acoustic beam steering. In the air, the resonance frequencies of the fast and slow axes are 420 Hz and 190 Hz respectively. When immersed in water, the resonance frequencies are reduced to 330 Hz and 160 Hz, respectively. The tilting angles of the mirror around the fast and slow axes follow a linear relationship with the driving current up to ±3.5°. With both axes driven simultaneously, stable and repeatable raster scanning patterns were obtained in both air and water. The micromachined water-immersible scanning mirrors could be useful for various scanning optical and acoustic microscopic imaging applications in both air and liquid environments.Graphical abstract
Source: Sensors and Actuators A: Physical - Category: Physics Source Type: research