All-Polymer Piezoelectric Elastomer with High Stretchability, Low Hysteresis, Self-Adhesion, and UV-Blocking as Flexible Sensor

Abstract

All-polymer piezoelectric elastomers that integrate selfpowered, soft, and elastic performance are attractive in the fields of flexible wearable electronics and human−machine interfaces. However, a lack of adhesion and UV-blocking performances greatly hinders the potential applications of elastomers in these emerging fields. Here, a high-performance piezoelectric elastomer with piezoelectricity, mechanical robustness, self-adhesion, and UV-resistance was developed by using poly(vinylidene fluoride) (PVDF), acrylonitrile (AN), acrylamide (AAm), and oxidized tannic acid (OTA) (named PPO). In this design, the dipole−dipole interactions between the PVDF and PAN chains promoted the content of β-PVDF, endowing high piezoelectric coefficient (d 33 , 58 pC/N). Besides, high stretchability (∼500%), supercompressibility (∼98%), low Young's modulus (∼0.02 MPa), and remarkable elasticity (∼13.8% hysteresis ratio) were achieved simultaneously for the elastomers. Inspired by the mussel adhesion chemistry, the OTA containing abundant catechol and quinone groups provided high adhesion (93.26 kPa to wood) and an exceptional UVblocking property (∼99.9%). In addition, the elastomers can produce a reliable electric signal output (V ocmax = 237 mV) and show a fast response (24 ms) when subjected to external force. Furthermore, the elastomer can be easily assembled as a wearable sensor for human physiological (body pulse and speech identification) monitoring and communication.

Tough, Antifreezing, and Piezoelectric Organohydrogel as a Flexible Wearable Sensor for Human–Machine Interaction

“…To clarify the composition and intermolecular interaction of the PAAN/Gly/Zn 2+ organohydrogels, Fourier transform infrared (FTIR) spectra were obtained (Figure S2). All groups had a characteristic peak at 2244 cm –1 related to the cyan (CN) absorption peak, indicating the presence of AN, and there were dipole–dipole interactions inside the organohydrogels . The 3451 and 3207 cm –1 bands were the symmetric and antisymmetric stretching vibration absorption bands of the amino group (NH 2 ), and 1675 cm –1 was the stretching vibration absorption peak of the carbonyl group (CO), confirming the successful introduction of AAm into the gels .…”

A Dual-Mode Pressure and Temperature Sensor

“…In recent years, with the advancement of sensor technology, tactile sensor technology has gradually emerged to mimic the sensing function of human skin. Flexible tactile sensors for force sensing can be divided into several types, such as piezoresistive [1][2][3], capacitive [4][5][6], piezoelectric [7][8][9], and optical sensors [10,11], according to the different conversion mechanisms between force and electrical signals. Each of these tactile sensors has different characteristics, and actual application scenarios require a flexible selection based on their advantages and disadvantages.…”