Stretchable, Long-Term Neural Implant on the Spinal Cord Could Restore Walking


So-called 'surface implants' have reached a roadblock. They can't be applied long-term to the spinal cord or brain, beneath the nervous system's protective envelope (known as the dura mater), because when nerve tissues move or stretch, they rub against the rigid devices. Repeated friction causes inflammation, scar tissue buildup, and rejection. Scientists from the Swiss Federal Institute of Technology in Lausanne (EPFL) now introduce the e-Dura implant, which is designed specifically for implantation on the surface of the brain or spinal cord. The neural implant combines electrical and chemical stimulation and has successfully made paralyzed rats walk again. Soft and stretchable, it is the first of its kind that can be implanted directly on the spinal chord without damaging it. Its silicon substrate is covered with cracked gold electric conducting tracks, and the electrodes are made of an innovative composite of silicon and platinum microbeads. They can be deformed in any direction, while still ensuring optimal electrical conductivity. A fluidic microchannel enables the delivery of pharmacological substances that will reanimate the nerve cells beneath the injured tissue.