Integration of conductive electrodes with 3D tissue models can have great potential for applications in bioelectronics, drug screening, and implantable devices. As conventional electrodes cannot be easily integrated on 3D, polymeric, and biocompatible substrates, alternatives are highly desirable. Graphene offers significant advantages over conventional electrodes due to its mechanical flexibility and robustness, biocompatibility, and electrical properties. However, the transfer of chemical vapor deposition graphene onto millimeter scale 3D structures is challenging using conventional wet graphene transfer methods with a rigid poly (methyl methacrylate) (PMMA) supportive layer. Here, a biocompatible 3D graphene transfer method onto 3D printed structure using a soft poly ethylene glycol diacrylate (PEGDA) supportive layer to integrate the graphene layer with a 3D engineered ring of skeletal muscle tissue is reported. The use of softer PEGDA supportive layer, with a 105 times lower Young's modulus compared to PMMA, results in conformal integration of the graphene with 3D printed pillars and allows electrical stimulation and actuation of the muscle ring with various applied voltages and frequencies. The graphene integration method can be applied to many 3D tissue models and be used as a platform for electrical interfaces to 3D biological tissue system.

中文翻译：

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石墨烯电极与3D骨骼肌组织模型的集成。

导电电极与3D组织模型的集成在生物电子，药物筛选和可植入设备中具有巨大的应用潜力。由于常规电极不能轻易地集成在3D，聚合物和生物相容性基材上，因此非常需要替代方案。石墨烯因其机械柔韧性，坚固性，生物相容性和电性能而比常规电极具有明显优势。然而，使用具有刚性聚（甲基丙烯酸甲酯）（PMMA）支撑层的常规湿式石墨烯转移方法，将化学气相沉积石墨烯转移到毫米级3D结构上是具有挑战性的。这里，报道了一种生物相容性3D石墨烯转移到3D打印结构上的方法，该方法使用了柔软的聚乙二醇二丙烯酸酯（PEGDA）支撑层，将石墨烯层与3D工程化的骨骼肌组织环整合在一起。与PMMA相比，杨氏模量低105倍的较软PEGDA支撑层的使用导致石墨烯与3D打印柱的保形整合，并允许在各种施加电压和频率下电刺激和激活肌肉环。石墨烯集成方法可以应用于许多3D组织模型，并且可以用作与3D生物组织系统电接口的平台。可以使石墨烯与3D打印的柱子共形整合，并可以通过各种施加的电压和频率对肌肉环进行电刺激和激励。石墨烯集成方法可以应用于许多3D组织模型，并且可以用作与3D生物组织系统电接口的平台。可以使石墨烯与3D打印的柱子共形整合，并可以通过各种施加的电压和频率对肌肉环进行电刺激和激励。石墨烯集成方法可以应用于许多3D组织模型，并且可以用作与3D生物组织系统电接口的平台。