Soft and Stretchable Implantable Electrodes to Interface with the Human Brain

Neural implants aim at restoring lost or impaired functions of the nervous system by electrical stimulation or recording of the brain. Current neural implants suffer from a mechanical mismatch compared to the soft host tissue, as they constrain mechanically the physiological<br/>motion of the central nervous system. This mismatch causes poor electrode-tissue contact, leading to unspecific stimulation or recording, as well as chronic scarring. At Neurosoft Bioelectronics, we overcome these fundamental limitations by developing soft and stretchable neural electrodes, using more compliant materials, that seamlessly interface with the brain, promoting the long-term bio-integration of the devices and reducing surgical risks.<br/><br/>Our electrodes are made of a thin-film (&lt;100 nm) of gold evaporated on a low modulus (&lt;1 MPa) silicone substrate, allowing for reversible elasticity while maintaining electrical properties. The electrode sites are coated with a rough platinum-silicone composite, which increases the electrochemical surface area and thus allowing for reduced interfacial impedance.<br/><br/>Neurosoft Bioelectronics has been working on the translation of these materials to the clinic by developing a subdural electrode, SOFT ECoG, to record from and electrically stimulate the surface of the brain.