A two-axis water-immersible micro scanning mirror using hybrid polymer and elastomer hinges

Abstract This paper reports a new two-axis water-immersible micro scanning mirror using hybrid polymer and elastomer hinges. The fast- and slow-axis hinges were made of stiff BoPET (biaxially-oriented polyethylene terephthalate) and soft elastomer nanocomposite (EN) loaded with alumina nanoparticles. Different concentrations of alumina nanoparticles in the base elastomer resin were tested to tune the elastic modulus of the elastomer nanocomposite. The testing results have shown a resonance frequency of 226 Hz for the fast axis and no mechanical resonance for the slow axis when the scanning mirror was immersed in water. 2D B-scan and 3D volumetric ultrasound microscopy were demonstrated by using the hybrid-hinge scanning mirror. The ability of scanning the slow axis at DC or very low frequencies allows a dense raster scanning pattern to be formed for improving both the imaging resolution and field of view.