Flexible graphene transistors for recording cell action potentials

TL;DR

This paper demonstrates flexible, biocompatible graphene transistors on polyimide that can reliably record cell action potentials with high signal quality, suitable for in-vivo bioelectronic applications.

Contribution

It introduces a fabrication method for flexible graphene SGFET arrays on polyimide and confirms their stability and performance in recording cell signals.

Findings

Transconductance and noise levels are comparable to rigid devices.

Devices maintain performance after repeated bending.

High signal-to-noise ratio in recording cardiomyocyte action potentials.

Abstract

Graphene solution-gated field-effect transistors (SGFETs) are a promising platform for the recording of cell action potentials due to the intrinsic high signal amplification of graphene transistors. In addition, graphene technology fulfils important key requirements for for in-vivo applications, such as biocompability, mechanical flexibility, as well as ease of high density integration. In this paper we demonstrate the fabrication of flexible arrays of graphene SGFETs on polyimide, a biocompatible polymeric substrate. We investigate the transistor's transconductance and intrinsic electronic noise which are key parameters for the device sensitivity, confirming that the obtained values are comparable to those of rigid graphene SGFETs. Furthermore, we show that the devices do not degrade during repeated bending and the transconductance, governed by the electronic properties of graphene, is unaffected by bending. After cell culture, we demonstrate the recording of cell action potentials from cardiomyocyte-like cells with a high signal-to-noise ratio that is higher or comparable to competing state of the art technologies. Our results highlight the great capabilities of flexible graphene SGFETs in bioelectronics, providing a solid foundation for in-vivo experiments and, eventually, for graphene-based neuroprosthetics.