Multifunctional high-density ultrasonic microsensor for ranging and 2D imaging

Ultrasound has been implemented as a powerful tool for noninvasive imaging and non-contact ranging. However, the size and single-function of traditional ultrasonic probes have limited their adaptability to complex application scenarios in the artificial intelligence era. This paper reports a multifunctional microsensor based on a piezoelectric micromachined ultrasonic transducer (pMUT) array that can be used for ranging and 2D imaging at the same time, in air, with a small working size (2x0.8mm(2)) and low driving voltage (10V). A back-end circuit was also designed to optimize the performance of the pMUT array, resulting in a peak-to-peak value of 158mV. The characterization of the multifunctional microsensor demonstrated that it is capable of performing ranging and 2D imaging simultaneously with high spatial resolution (similar to 1mm in ranging and similar to 0.2x0.2mm(2) in 2D-imaging), even in complex application scenarios. This paper describes a system that integrates micro-electro-mechanical systems device, back-end circuit, imaging algorithm, and denoising algorithm, which allow the microsensor to provide multiple functions. This makes it a promising tool for a wide range of human-machine interaction applications, such as gesture recognition, robotics, and healthcare.