GRAphene-based Flexible neural Interfaces for the control of Neuroprosthetic devices (GRAFIN)

Purpose and goal

The goal of the GRAFIN project was to develop electrodes based on graphene as part of FLAG-ERA’s Graphene Flagship which aims to bring graphene innovations out of the labs. The electrodes were tested in the peripheral and central nervous systems of animals, and our part consisted of non-invasive, in human evaluations (including amputee subjects) that showed the viability of these electrodes. Our testing focused on myoelectric control which is used to control prosthetic hands as well as electrotactile feedback, which can be used to give sensations when the prosthesis touch something.

Expected results and effects

Graphene based electrodes showed good biocompatibility and improved performance compared to metal electrodes in-vivo. In non-invasive applications, their myoelectric control performance was similar to silver/silver-chloride electrodes (gold standard) and they appear to be better at providing electrotactile feedback. A closed-loop prosthetic control system with electrotactile feedback was developed and tested with the graphene electrodes. A preliminary outcome of this project is that graphene electrodes could be used to provide feedback to prosthetic limbs.

Planned approach and implementation

The survival of primary neurons and Schwann cells was evaluated in-vitro. Then, in-vivo studies were performed in animal models to successfully evaluate biocompatibility, nerve stimulation and neural recordings. Measurements with humans were done by inviting people with and without upper limb absence to participate. Participant signed an informed consent form before participating. Participants controlled virtual limbs, tested the electrotactile feedback, and tested the prosthetic control system with electrotactile feedback.