MIT researchers create 3D printed soft brain implants

At MIT, a team of researchers is currently working on 3D printing neural implants as soft and flexible as rubber. Traditionally, brain implants are made of metal – this new method would allow for the brain implant to better adapt to the contours of our brain, thus avoiding inflammation and the accumulation of scar tissue. At the moment, the team is still in the testing phase. It has already implanted the 3D printed neural device made from a conductive polymer in a mouse, and has been able to obtain a precise image of the brain’s activity.

More generally, in the medical sector, and more particularly in dentistry, additive manufacturing is helping to design tailor-made implants that are better adapted to the morphology of each patient. But it can also be used throughout the research and development phase, to understand complex structures and facilitate the deployment of solutions. When it comes to the study of the brain, for example, one of the most complex vital organs, 3D printing can help design devices for study, testing, monitoring, etc. The team of Xuanhe Zhao, a professor of mechanical engineering and of civil and environmental engineering at MIT, has therefore used 3D printing technologies to develop flexible brain implants capable of monitoring the organ’s activity over long periods of time without aggravating the surrounding tissue.

3D printing of the electrode | Credits: MIT

The use of polymer 3D printing

Based on the finding that metal electrodes and implants were not suitable in the long run, the researchers opted for a polymer that had to be conductive. Today, most of the conductive polymer solutions available on the market are used as antistatic coatings, i.e. in liquid form. Hyunwoo Yuk, a graduate student in the Zhao group at MIT, adds: “The liquid form is mostly for homogenous coatings, and it’s difficult to use this for any two-dimensional, high-resolution patterning. In 3D, it’s impossible.” Researchers therefore had to develop another form, a kind of hydrogel.