Implantable carbon fiber brain electrodes perform well in animal testing

The University of Michigan has developed a very small and implantable carbon fiber electrode. The electrode has been demonstrated in rats and has the potential to provide a long-term brain-computer interface. Researchers on the project note that the electrode can capture the scope and nuance of electrical signals over lengthy periods.

Researchers believe that someday the implantable carbon fiber electrodes could lead to advances for humans, boosting the quality of life for people with ailments ranging from amputation to spinal injuries. The electrodes could control advanced prosthetic devices, stimulate the sacral nerve to restore bladder control, or stimulate the cervical vagus nerve to treat epilepsy.

The carbon fiber electrodes might also be a possible treatment for Parkinson's disease. Research at the University of Michigan shows the promise of carbon fiber electrodes for delivering electrical signals from a rat's brain to an outside computer without resulting in damage to the brain tissue. Directly implanting the electrodes into the brain captures bigger and more specific brain signals than current technologies.

Researcher Elissa Welle from the University of Michigan Department of biomedical engineering says that while they're interfaces out there that can be implanted directly into the brain, for a variety of reasons, they're only able to last from a few months to a few years. She also notes that opening the skull for procedures involving the brain is a big deal.

Currently, silicon is most commonly used in brain implants because of its ability to conduct electricity and its use in cleanroom technology. The human body sees silicon as a foreign substance and can lead to scar tissue formation over long periods. Silicon also eventually degrades and is no longer able to capture brain signals requiring removal.

Since carbon is a key element in the body and is present in organic molecules, including proteins, carbohydrates, and fats, the material could be the answer to getting high-quality signals with an interface able to last years rather than months. Researchers laser cut and sharpened carbon fibers into subcellular electrodes in the lab using a small blowtorch opening the door for implantable electrodes the body is more likely to accept.