Wearable sensing electronic devices based on hydrogel are gradually developing towards multifunction and portability, however, efficiently harvesting energy from the surrounding environment to power traditional hydrogel-based wearable electronic devices is a major challenge. The assembly of multilayer heterogeneous hydrogels is a potential strategy to address this challenge. Herein, inspired by the structure of diodes, a diode-like integrated hydrogel composed of a three-tier structure of anionic polyelectrolyte hydrogel, polyacrylamide hydrogel and cationic polyelectrolyte hydrogel is developed. By the connection of polyacrylamide hydrogel, the composite hydrogel exhibits excellent structural stability and mechanical properties. Notably, due to the introduction of MXene ion-conducting microchannels, the directional transport of free cations and anions ionized by anionic and cationic polyelectrolytes is achieved, thereby improving the conductivity (74.58 mS/cm), sensing (gauge factor = 7.47) and piezoionic output performance of the composite hydrogel. The composite hydrogel-based sensor can sense tiny facial movements and recognize the direction of human movement, and the composite hydrogel-based piezoionic generator exhibit more efficient mechanical-electric conversion performance, which can output the maximum voltage of 1410 mV, current of 28 μA, and power density of 2.9 mW/m2 for a composite hydrogel of 5×5 cm2. The integration of multilayer heterogeneous hydrogels proposes a versatile strategy for the development of high-performance hydrogel-based self-powered sensing electronic devices, expanding the application of hydrogels in artificial intelligence and human-computer interaction.

中文翻译：

---

用于压电发生器和传感器的二极管状集成水凝胶


基于水凝胶的可穿戴传感电子设备正逐渐向多功能和便携性发展，然而，有效地从周围环境中收集能量为传统的基于水凝胶的可穿戴电子设备供电是一项重大挑战。多层异质水凝胶的组装是应对这一挑战的潜在策略。本文受二极管结构的启发，开发了一种由阴离子聚电解质水凝胶、聚丙烯酰胺水凝胶和阳离子聚电解质水凝胶三层结构组成的二极管状集成水凝胶。通过与聚丙烯酰胺水凝胶的连接，复合水凝胶表现出优异的结构稳定性和机械性能。值得注意的是，由于 MXene 离子导电微通道的引入，实现了自由阳离子和阴离子和阳离子聚电解质电离的阴离子的定向传输，从而提高了复合水凝胶的电导率 （74.58 mS/cm）、传感 （标值 = 7.47） 和压电离子输出性能。基于复合水凝胶的传感器可以感应微小的面部运动并识别人体运动的方向，复合水凝胶基压电发生器表现出更高效的机电转换性能，可输出最大电压 1410 mV，电流为 28 μA，功率密度为 2.9 mW/m2，适用于 5×5 cm2 的复合水凝胶。多层异质水凝胶的集成为开发高性能基于水凝胶的自供电传感电子设备提出了一种多功能策略，扩大了水凝胶在人工智能和人机交互中的应用。