PROJECT TITLE :

Zero-Bending Piezoelectric Micromachined Ultrasonic Transducer (pMUT) With Enhanced Transmitting Performance

ABSTRACT:

A piezoelectric micromachined ultrasonic transducer (pMUT) has enabled various exciting ultrasonic applications. However, residual stress and initial buckling may worsen the transmitting sensitivity of a pMUT, and conjointly limit its application and commercialization. In this paper, we report a replacement innovative pMUT with a wonderfully flat membrane, i.e., zero-bending membrane. Leveraging on the strain-free AlN thin film, framelike prime electrode layout, and integrated vacuum cavity, the initial deflection of suspended membrane is considerably suppressed to solely zero.005%. The transmitting sensitivity of the zero-bending pMUT is measured as 123 nm/V at a resonant frequency of two.twenty one MHz, that is 450% over that of the reference pMUT with slightly non-zero initial deflection. Compared with the simulation results, the measured data of zero-bending pMUT achieve ninety four.5% of its ideal transmitting sensitivity. It's solid evidence that our approach is an efficient and reliable way to beat the residual stress and therefore the initial buckling issue. [2015-0093]