Polymer gels, such as hydrogels, have been widely used in biomedical applications, flexible electronics, and soft machines. Polymer network design and its contribution to the performance of gels has been extensively studied. In this study, the critical influence of the solvent nature on the mechanical properties and performance of soft polymer gels is demonstrated. A polymer gel platform based on poly(ethylene glycol) (PEG) as solvent is reported (PEGgel). Compared to the corresponding hydrogel or ethylene glycol gel, the PEGgel with physically cross-linked poly(hydroxyethyl methacrylate-co-acrylic acid) demonstrates high stretchability and toughness, rapid self-healing, and long-term stability. Depending on the molecular weight and fraction of PEG, the tensile strength of the PEGgels varies from 0.22 to 41.3 MPa, fracture strain from 12% to 4336%, modulus from 0.08 to 352 MPa, and toughness from 2.89 to 56.23 MJ m^–3. Finally, rapid self-healing of the PEGgel is demonstrated and a self-healing pneumatic actuator is fabricated by 3D-printing. The enhanced mechanical properties of the PEGgel system may be extended to other polymer networks (both chemically and physically cross-linked). Such a simple 3D-printable, self-healing, and tough soft material holds promise for broad applications in wearable electronics, soft actuators and robotics.

中文翻译：

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坚韧、透明、可 3D 打印和自我修复的聚（乙二醇）-凝胶 (PEGgel)

聚合物凝胶，如水凝胶，已广泛用于生物医学应用、柔性电子产品和软机械。聚合物网络设计及其对凝胶性能的贡献已被广泛研究。在这项研究中，证明了溶剂性质对软聚合物凝胶的机械性能和性能的关键影响。报道了一种基于聚乙二醇（PEG）作为溶剂的聚合物凝胶平台（PEGgel）。与相应的水凝胶或乙二醇凝胶相比，具有物理交联聚（甲基丙烯酸羟乙酯-co-丙烯酸）具有高拉伸性和韧性、快速自愈性和长期稳定性。根据 PEG 的分子量和分数，PEG 凝胶的拉伸强度从 0.22 到 41.3 MPa，断裂应变从 12% 到 4336%，模量从 0.08 到 352 MPa，韧性从 2.89 到 56.23 MJ m ^-3不等。最后，演示了 PEGgel 的快速自愈，并通过 3D 打印制造了自愈气动致动器。PEGgel 系统增强的机械性能可以扩展到其他聚合物网络（化学和物理交联）。这种简单的 3D 可打印、自我修复和坚韧的软材料有望在可穿戴电子设备、软致动器和机器人技术中广泛应用。