A Computational Piezoelectric Micro-Machined Ultrasonic Transducer Toward Acoustic Communication

Piezoelectric micro-machined ultrasonic transducers (pMUTs) are gaining popularity in integrated smart ultrasonic systems. In this letter, we report a pMUT toward acoustic communication with mechanical computation ability for the first time. The novel pMUT design can successfully operate 2-bit OR, XOR, XNOR, and NOT mechanical logic operations based on resonance frequency tuning. The proposed mechanical actuation can operate steady and reliable binary amplitude shift keying (BASK), binary frequency shift keying (BFSK) modulations with its naturally detached resonance modes in a single device. Such an idea can greatly reduce the complexity and cost of the acoustic communication system design in terms of hardware. A minimum response time of about 0.14 ms is achieved with the proposed device, equivalent to a bit rate over 3.5 kb/s. In addition, a higher data rate can be achieved since the operating speed can be greatly improved by impedance matching and shrinking the pMUT size.