Recently, flexible and wearable electronics have gained considerable research interest due to their potential applications in wearable devices, energy storage materials, electronic skins, sensors, etc. Compared to elastomers, hydrogels demonstrate more potential for flexible electronics because of their biomimetic structures, suitable mechanical properties and excellent biocompatibility. Among all the designs, nanocomposite hydrogel-based strain and pressure sensors which can transmit external stimulus to electrical signals have been intensely investigated due to their high mechanical strength, considerable conductivity and outstanding sensitivity. Numerous reports have been dedicated to the designs, preparations and applications of nanocomposite hydrogels. This review provides an up-to-date and comprehensive summary of research progresses of nanocomposite hydrogel-based strain and pressure sensors including designing strategies, preparing methods and applications of the five nanofiller based hydrogel sensors including carbon nanotube based, graphene oxide based, MXene based, polymer nanofiller based and other nanofiller based sensors. Representative cases are carefully selected and discussed regarding the fabrication, merits and demerits, respectively. Finally, perspectives and challenges are presented for the designs of future nanocomposite hydrogel-based strain and pressure sensors.

中文翻译：

---

基于纳米复合水凝胶的应变和压力传感器：综述

近年来，由于柔性和可穿戴电子产品在可穿戴设备，能量存储材料，电子皮肤，传感器等方面的潜在应用，已引起了广泛的研究兴趣。与弹性体相比，水凝胶由于具有仿生结构，合适的机械性能和出色的生物相容性，因此在柔性电子领域显示出更大的潜力。在所有设计中，由于纳米复合水凝胶基应变和压力传感器具有很高的机械强度，相当大的导电性和出色的灵敏度，因此可以将外部刺激传递给电信号，因此受到了广泛的研究。大量报告致力于纳米复合水凝胶的设计，制备和应用。这篇综述提供了基于纳米复合水凝胶的应变和压力传感器研究进展的最新，最全面的摘要，包括基于纳米填料的五种基于水纳米管的水凝胶传感器的设计策略，制备方法和应用，基于氧化石墨烯，基于MXene，基于聚合物纳米填料的传感器和其他基于纳米填料的传感器。精心选择代表性案例，并分别讨论其制造，优缺点。最后，提出了未来基于纳米复合水凝胶的应变和压力传感器设计的观点和挑战。