The goal of this project is to design and fabricate a novel ultrasonic fingerprint sensor based on high-frequency Piezoelectric Micromachined Ultrasonic Transducers (PMUTs). Present fingerprint sensors in portable devices, such as capacitive fingerprint sensors, have failed to gain wide acceptance due to their susceptibility to contamination from oils, perspiration and dirt. Ultrasonic fingerprint sensors solve these problems, but devices currently available are too large and costly for deployment in consumer devices. Here, an ultrasonic fingerprint sensor based on PMUTs fully integrated with CMOS ASIC is proposed and demonstrated. 1-D pulse-echo imaging of steel phantom using 20×8 PMUT array with electronic scanning is demonstrated with echo voltage amplitude ~150 mV. 2-D pulse-echo imaging of PDMS fingerprint phantom with ~600 um pitch similar to human fingerprint pattern is demonstrated.
- Lu, Y., Shelton S.E., and Horsley D.A., “High Frequency and High Fill Factor Piezoelectric Micromachined Ultrasonic Transducers Based on Cavity SOI Wafers”, Hilton Head 2014 Solid-State Sensors, Actuators & Microsystems Workshop, Hilton Head Island
- Yipeng Lu; Heidari, A; Shelton, S.; Guedes, A; Horsley, D.A, “High frequency piezoelectric micromachined ultrasonic transducer array for intravascular ultrasound imaging,” Micro Electro Mechanical Systems (MEMS), 2014 IEEE 27th International Conference on , vol., no., pp.745,748, 26-30 Jan. 2014