Flexible Piezoelectric Micromachined Ultrasonic Transducers Towards New Applications

This paper presents flexible piezoelectric micromachined ultrasonic transducers (PMUT) on thin polymer substrate. The flexible PMUT is based on AIN piezoelectric thin film with a new structural configuration optimized for flexibility. The measured resonant frequency, effective coupling coefficient and displacement sensitivity are 2.58 MHz, 1.42% and 30 nm/V, respectively, which are on par with those of a conventional PMUT on a silicon substrate. The flexible PMUT introduced in this work will find new applications in medical imaging, therapeutics, surgery, industry and consumer electronics, thanks to the potential merits of mechanical compliance, light weight, small element size, large array area and high integration level.