Optimizing the performance of piezoelectric pressure sensors: The key role of ZnO particles’ properties

Reliance on wearable electronics for physiological data collection has grown rapidly, driving demand for pressure sensors with stable, reproducible performance capable of continuous monitoring of physiological data. Mechanical stimuli can be converted into electrical signals through effects such as piezoelectricity, enabling sensors with high sensitivity and extended range. Among sensor materials, polydimethylsiloxane (PDMS) and zinc oxide (ZnO) are particularly noteworthy: PDMS offers stability and flexibility, while ZnO is non-toxic and can be synthesized with diverse properties. Given the influence of material properties on performance, sensors based on microwave-assisted grown ZnO particles embedded in PDMS matrices were developed. Films of ZnO wires, plates, and flowers mixed with PDMS, were deposited by doctor blade and sandwiched between electrodes. Sensors with PDMS, ZnO flowers, and wires exhibited a sensitivity of around 0.03 V·kPa -1 , whereas the plate-based devices reached 0.021 V·kPa -1 . Wire-based sensors exhibited a detection limit of 0.16 kPa and response time under 30 ms. These results highlight the critical role of piezoelectric material properties in sensor performance. Wire- and flower-based sensors outperformed previously reported devices while maintaining scalable, cost-effective fabrication, holding strong promise for biomedical applications, such as gait analysis and tremor detection.