An Implantable, Ultralow Distortion Bioelectronic Interface Integrating Light-Emitting Diodes and Graphene Field-Effect Transistors.

Microscale inorganic light-emitting diodes (μ-ILEDs) and field-effect transistors (FETs) are two widely used electronic components for high-resolution neural modulations and multimodal recordings. Integrating these devices into minimally invasive bioelectronic interfaces provides opportunities for investigating neural signaling at the cellular and molecular levels. However, such integration poses challenges due to crosstalk-induced signal distortions. Here, we present an implantable Opto-FET bioelectronic interface that incorporates μ-ILEDs and graphene-FETs in a compact configuration with ultralow distortions. Our work systematically identifies and mitigates two major sources of distortion: electromagnetic interference and photon-induced doping in graphene channels. We demonstrate that a combination of electromagnetic shielding and a light-blocking barrier effectively suppresses the distortion, reducing the maximum signal distortion level from 10-15% to 0.3-0.9%. We finally validate the distortion suppression strategy in vivo through real-time electrophysiological recordings during the operation of the μ-ILED. Overall, this study establishes a foundation for the development of next-generation multimodal neural probes enabling simultaneous optical stimulation and neural recordings.