Living tissues are non-linearly elastic materials that exhibit viscoelasticity and plasticity. Man-made, implantable bioelectronic arrays mainly rely on rigid or elastic encapsulation materials and stiff films of ductile metals that can be manipulated with microscopic precision to offer reliable electrical properties. In this study, we have engineered a surface microelectrode array that replaces the traditional encapsulation and conductive components with viscoelastic materials. Our array overcomes previous limitations in matching the stiffness and relaxation behaviour of soft biological tissues by using hydrogels as the outer layers. We have introduced a hydrogel-based conductor made from an ionically conductive alginate matrix enhanced with carbon nanomaterials, which provide electrical percolation even at low loading fractions. Our combination of conducting and insulating viscoelastic materials, with top-down manufacturing, allows for the fabrication of electrode arrays compatible with standard electrophysiology platforms. Our arrays intimately conform to the convoluted surface of the heart or brain cortex and offer promising bioengineering applications for recording and stimulation.

活组织是表现出粘弹性和塑性的非线性弹性材料。人造的可植入生物电子阵列主要依靠刚性或弹性封装材料和延展性金属的硬膜，可以用微观精度进行操作以提供可靠的电性能。在这项研究中，我们设计了一种表面微电极阵列，用粘弹性材料代替传统的封装和导电元件。我们的阵列通过使用水凝胶作为外层克服了以前在匹配软生物组织的刚度和松弛行为方面的限制。我们推出了一种基于水凝胶的导体，该导体由碳纳米材料增强的离子导电藻酸盐基质制成，即使在低负载分数下也能提供电渗透。我们将导电和绝缘粘弹性材料与自上而下的制造相结合，可以制造与标准电生理学平台兼容的电极阵列。我们的阵列与心脏或大脑皮层的复杂表面紧密贴合，并为记录和刺激提供了有前途的生物工程应用。