Stiff Biodegradable Needle
Floating Soft Electric Leads Nanostructured Surface
Biodegradation
Biodegradation
Insulating Sheath Microelectrode
Implants that understand the brain
Nanostructured Surface
Brain implants need to be well adapted to the natural brain environment. Researchers in the Brain Micro Snooper project are working to develop improved brain implants, work which brings the prospect of restoring certain functions to disabled people a step closer, as Dr Gaëlle Offranc-Piret explains. An individual who has been paralysed following a traffic accident may retain normal neuronal function, with neurons in the brain still sending signals out to the rest of the body. The problem lies elsewhere in the body. “The problem is in communication to the nerves,” says Dr Gaelle Offranc-Piret, a researcher in the BrainTech research laboratory at Grenoble, part of INSERM. A reliable brain implant could help record information on neural activity at the neuron’s scale, a major step towards effective intervention; this is a topic at the heart of Dr Offranc-Piret’s work in the ERC-funded Brain Micro Snooper project. “We aim to develop brain implants with micro-electrodes that will attach to neurons and detect their action potentials in the long term,” she outlines. “The goal is to bring these implants to the clinic. In order to achieve this we need to pay a lot of attention to the materials that we use, so that it has a higher probability of clinical transfer.”
Brain Micro-Snooper This research holds relevance beyond cases of paralysis, as the implant could be adapted to several different pathologies, including epilepsy, neurodegenerative disorders and
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certain types of tumours, while it could also be used in therapeutic brain-computer interfaces. The focus at this stage however The implant before surgical insertion.
A nanostructured electrode.
is on developing an implant to record action potentials, with Dr Offranc-Piret using fairly conventional materials. “We are looking at certain types of insulating polymer such as polyimides or parylenes, and we are also varying the conductor part using gold, platinum or PEDOT:PSS. We are then trying to compare the different possibilities in terms of performance,” she says. The shape of the implant is however the most important consideration. “The aim is really to be as biomimetic as possible when it comes to the shape of the implants so that they are seen by the brain environment just as a brain cell,” continues Dr Offranc-Piret. By minimising the dimensions of the implant, Dr Offranc-Piret aims to reduce the flexibility mismatch between implant and brain materials, and therefore the disruption to surrounding cells once the implant is introduced. Also, researchers are using nanostructured or microstructured materials for the electrode. “Nothing in the brain is really entirely flat, everything is moving around to some extent. The membranes are quite packed,” outlines Dr Offranc-Piret. By modifying the surface of the material, using micro- and nontechnology methods,
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