With the rapid development of 5G/6G communications, smart sensors, biomedicine and the Internet of Things (IoT), traditional piezoelectric devices are facing challenges in miniaturization, integration and high-frequency performance. To address this, piezoelectric MEMS technology has become an effective way to break through, due to its high sensitivity, low power consumption and large-scale manufacturing. This technology achieves the mutual conversion of mechanical energy and electrical energy through the piezoelectric effect, which has shown numerous advantages in the fields of surface acoustic wave (SAW) devices, bulk acoustic wave (BAW) devices, piezoelectric micromechanical ultrasonic transducers (PMUT), and microspeaker. In this field, our team is mainly focusing on the research and development of SAW devices and PMUTs.

Fig. 1 Market Prospects of Piezoelectric MEMS Devices

SAW devices ultilize the characteristics of the acoustic waves propagating on the piezoelectric substrate surface to realize signal filtering and sensing. The related filters, delay lines, and sensors have been widely used in the fields of RF communications, environmental monitoring and so on. On this topic, our team mainly focus on the theoretical research, numerical research, optimization design and other scientific research.

Fig. 2 SAW sensing unit^[1]

Fig. 3 Finit element simulation of SAW on a piezoelectric substrate^[2]

PMUTs use the mechanical vibration of piezoelectric film to transmit and receive ultrasound waves. They have shown great potentials in the fields of medical imaging (such as portable ultrasound probes), industrial non-destructive testing, consumer electronics (gesture recognition, distance sensing), and autonomous driving (close-range obstacle avoidance). Its miniaturization provide new possibilities for wearable devices and implantable medical devices. On this topic, our team mainly conduct research on numerical research, optimization design, and engineering applications.

Fig. 4 Schematic diagram of PMUT device structure^[3]

References

1] https://www.transense.com/

[2] Collins D J, Devendran C, Ma Z, et al. Acoustic tweezers via sub–time-of-flight regime surface acoustic waves[J]. Science advances, 2016,2(7): e1600089.

[3] Soukup B H. Design of piezoelectric micromachined ultrasonic transducer (PMUT) arrays for intrabody networking applications[D]. Northeastern University, 2017.