Department of Materials Science and Engineering, Penn State University, University Park, PA 16802, USA.
Department of Biomedical Engineering, Penn State University, University Park, PA 16802, USA.
Sensors (Basel). 2022 Jul 27;22(15):5614. doi: 10.3390/s22155614.
The receive sensitivity of lead zirconate titanate (PZT) piezoelectric micromachined ultrasound transducers (PMUTs) was improved by applying a DC bias during operation. The PMUT receive sensitivity is governed by the voltage piezoelectric coefficient, . With applied DC biases (up to 15 V) on a 2 μm PbZrTiO film, e increased 1.6 times, permittivity decreased by a factor of 0.6, and the voltage coefficient increased by ~2.5 times. For released PMUT devices, the ultrasound receive sensitivity improved by 2.5 times and the photoacoustic signal improved 1.9 times with 15 V applied DC bias. B-mode photoacoustic imaging experiments showed that with DC bias, the PMUT received clearer photoacoustic signals from pencil leads at 4.3 cm, compared to 3.7 cm without DC bias.
通过在操作过程中施加直流偏压，可以提高锆钛酸铅（PZT）压电微加工超声换能器（PMUT）的接收灵敏度。PMUT 的接收灵敏度由电压压电系数 决定。在 2μm PbZrTiO 薄膜上施加高达 15V 的直流偏压后，e 增加了 1.6 倍，介电常数降低了 0.6 倍，电压系数增加了约 2.5 倍。对于释放的 PMUT 器件，施加 15V 直流偏压后，超声接收灵敏度提高了 2.5 倍，光声信号提高了 1.9 倍。B 模式光声成像实验表明，与无直流偏压相比，施加直流偏压后，PMUT 从 4.3cm 处的铅笔芯接收到的光声信号更清晰。
