Hydrogels offer tissue-like compliance, stretchability, fracture toughness, ionic conductivity and compatibility with biological tissues. However, their electrical conductivity (<100 S cm⁻¹) is inadequate for digital circuits and applications in bioelectronics. Furthermore, efforts to increase conductivity by using hydrogel composites with conductive fillers have led to compromises in compliance and deformability. Here, we report a hydrogel composite that has a high electrical conductivity (>350 S cm⁻¹) and is capable of delivering direct current while maintaining soft compliance (Young’s modulus < 10 kPa) and deformability. Micrometre-sized silver flakes are suspended in a polyacrylamide–alginate hydrogel matrix and, after going through a partial dehydration process, the flakes form percolating networks that are electrically conductive and robust to mechanical deformations. To illustrate the capabilities of our silver–hydrogel composite, we use the material in a stingray-inspired swimmer and a neuromuscular electrical stimulation electrode.

水凝胶具有类似组织的顺应性、可拉伸性、断裂韧性、离子电导率以及与生物组织的相容性。然而，它们的电导率（<100 S cm ^-1）不足以用于数字电路和生物电子学中的应用。此外，通过使用具有导电填料的水凝胶复合材料来增加导电性的努力导致了柔顺性和可变形性的妥协。在这里，我们报告了一种具有高电导率（>350 S cm ^-1) 并且能够提供直流电，同时保持柔软的顺应性（杨氏模量 < 10 kPa）和可变形性。微米大小的银薄片悬浮在聚丙烯酰胺-海藻酸盐水凝胶基质中，经过部分脱水过程后，薄片形成渗透网络，该网络具有导电性并且对机械变形具有鲁棒性。为了说明我们的银-水凝胶复合材料的能力，我们在受黄貂鱼启发的游泳者和神经肌肉电刺激电极中使用了该材料。