Electrode design promises potential for treating neurological disorders and beyond

Implantable electrodes that induce electrical stimulation of peripheral nerves are becoming more common for treating drug-resistant neurological disorders including depression, epilepsy, and chronic pain. Practical applications now mostly focus on large nerve fiber stimulation, with implanted electrodes typically made up of thin biocompatible films like hydrogels or elastomers.

In contrast, “cuff” electrodes that wrap around nerves to enable more precise nerve stimulation are emerging, promising to broaden the range of applicability. But they require advanced surgical skills and still risk damaging delicate nerves.

Goto et al. developed a self-folding cuff-type thin film electrode that better conforms to thin peripheral nerves, eliminating the risk and requisite surgical precision.

“Using this thin film, we successfully controlled the movement of a rat’s leg by electrically stimulating its sciatic nerve,” said author Toichiro Goto.

Less than 1 micrometer thick, the film is made of three layers: graphene, parylene, and calcium alginate, a polysaccharide found in some seaweed that dissolves when the film self-folds. Once assembled, the electrode film remains stable and resistant to physical and chemical changes; and the non-toxic materials make it highly biocompatible.

Embedded in the film, an array of holes enables electrical stimulation of inner nerve bundles and can control the direction and limit the area of self-folding to allow long biological tissues to become efficiently encapsulated within the film. Additionally, the graphene functions as an antenna and sensor, making it possible to electrically stimulate peripheral nerves and measure nerve activity wirelessly.

“We hope our research emphasizes the potential technical breakthrough of improving nerve adhesion through the self-folding of cuff-type thin film electrodes,” said Goto.

Source: “Self-folding graphene cuff electrodes for peripheral nerve stimulation,” by Toichiro Goto, Koji Sakai, Yosuke Mizuno, Masumi Yamaguchi, and Tetsuhiko F. Teshima, APL Materials (2025). The article can be accessed at https://doi.org/10.1063/5.0255032 .

This paper is part of the 2D Materials for Biomedical Applications Collection, learn more here .