Barcelona-based startup Inbrain Neuroelectronics has secured permission for the world’s first experiments with a promising graphene neuroimplant. Unlike traditional metal electrodes for reading the activity of brain cells, graphene is not subject to electrochemical changes, which will allow for more powerful tissue stimulation with a pronounced therapeutic effect. Graphene implants will not just read signals, they will heal.
Image source: Inbrain Neuroelectronics
Immersing implant electrodes in the brain or in close contact with living brain tissue is equivalent to immersing metal in an electrolyte. When even a weak electrical signal passes at the electrolyte/metal interface, so-called Faraday (electrochemical redox) processes occur, which gradually reduce the efficiency of the electrodes. The situation is aggravated if it is necessary to stimulate brain tissue with stronger impulses, which, for example, must be done for therapy (treatment).
Engineers at Inbrain Neuroelectronics proposed to circumvent this limitation using graphene electrodes. Graphene is ordinary carbon with high conductivity due to its structure. In an electrolyte it is neither oxidized nor reduced. A graphene sensor implanted into the brain in the form of an array of micron-sized dots will be able to read impulses from the patient’s nervous tissue and, if necessary, return stimulating impulses of increased power to it without fear of causing deterioration in the operation of the electrodes, and it is better not to interfere with the brain once again, with which everything will agree.
In a world first, the Inbrain sensor will be tested this summer at the University of Manchester during surgery to remove a patient’s brain tumor. The Inbrain sensor will be used in this case as a recorder of healthy tissue to determine the boundaries of the tumor, so as not to remove the patient’s brain areas unaffected by the disease. At the next stage, the sensor will be tested on a patient with Parkinson’s disease. The interface in this case is placed in the area of the nigrostriatal pathway, which will help to record the patient’s brain activity with high resolution during his activity.
At the second stage, the sensor will also not be directly used to restore the patient’s health. His task will be to identify symptoms indicating improvement or worsening of the disease. This should help reduce the use of often unsafe medications by up to 50%.
At the third stage of testing the graphene neurosensor, it will be used directly for the treatment of Parkinson’s disease. The proposed solution will be able to withstand a 200 times stronger pulse than metal electrodes without triggering Faraday reactions. The company has already tested graphene implants for biocompatibility with brain tissue in “large animals” and is confident that people will not have compatibility problems with graphene.
The production of graphene sensors is quite simple, the company says. They can be produced at any semiconductor plant, even not the most modern one. Their thickness is 10 microns, and the contact points will range in size from 25 to 300 microns.