Soft and stretchable electronics have emerged as highly promising tools for biomedical diagnosis and biological studies, as they interface intimately with the human body and other biological systems. Most stretchable electronic materials and devices, however, still have Young’s moduli orders of magnitude higher than soft bio-tissues, which limit their conformability and long-term biocompatibility. Here, we present a design strategy of soft interlayer for allowing the use of existing stretchable materials of relatively high moduli to versatilely realize stretchable devices with ultralow tissue-level moduli. We have demonstrated stretchable transistor arrays and active-matrix circuits with moduli below 10 kPa—over two orders of magnitude lower than the current state of the art. Benefiting from the increased conformability to irregular and dynamic surfaces, the ultrasoft device created with the soft interlayer design realizes electrophysiological recording on an isolated heart with high adaptability, spatial stability, and minimal influence on ventricle pressure. In vivo biocompatibility tests also demonstrate the benefit of suppressing foreign-body responses for long-term implantation. With its general applicability to diverse materials and devices, this soft-interlayer design overcomes the material-level limitation for imparting tissue-level softness to a variety of bioelectronic devices.

柔软且可拉伸的电子产品已成为生物医学诊断和生物学研究中非常有前途的工具，因为它们与人体和其他生物系统密切相关。然而，大多数可拉伸电子材料和设备的杨氏模量仍然比软生物组织高几个数量级，这限制了它们的顺应性和长期生物相容性。在这里，我们提出了一种软中间层的设计策略，允许使用现有的相对高模量的可拉伸材料来通用地实现具有超低组织水平模量的可拉伸装置。我们已经展示了模量低于 10 kPa 的可拉伸晶体管阵列和有源矩阵电路，比当前最先进技术低两个数量级。得益于对不规则和动态表面的更高的顺应性，采用软夹层设计创建的超软设备实现了离体心脏上的电生理记录，具有高适应性、空间稳定性和对心室压力影响最小。体内生物相容性测试还证明了抑制异物反应对于长期植入的好处。由于其对各种材料和设备的普遍适用性，这种软夹层设计克服了材料水平的限制，为各种生物电子设备提供了组织水平的柔软度。