Highly Efficient T-shaped Piezoelectric Micromachined Transducer

Abstract— Piezoelectric micromachined ultrasonic transducers (PMUTs) have gained significant attention for different applications within acoustic sensing because of their unique characteristics, such as higher quality factor and fabrication yield, etc. This paper introduces a novel mechanical geometry for piezoelectric transducers to improve energy conversion efficiency. The proposed design comprises a T-shaped cantilever with a pair of proof masses at its tip location. The proposed geometry efficiency in receiving and transmitting the acoustic waves is surveyed through simulations and experimental measurements. Experimental measurements reveal that the first mode shape, occurring at approximately 1100 Hz, represents the fundamental resonant frequency, characterized by the largest displacement. The second mode shape, appearing at around 4700 Hz, exhibits less pronounced displacement; it can be essential for applications requiring higher frequency responses. The energy conversion efficiency improvement obtained thanks to the design, eliminates the need for employing specialized signal conditioning circuits and potentially reduces the cost and complexity of the entire system.