MIT scientists 3D print soft, rubbery brain implants

Scientists at MIT have developed a way to 3D print soft, flexible neural implants that they say can gently conform to the brain's contours and monitor activity over longer periods.

Such flexible electronics could be softer alternatives to existing metal-based electrodes designed to monitor brain activity, the researchers said.

They may also be useful in brain implants that stimulate neural regions to ease symptoms of epilepsy, Parkinson's disease, and severe depression, according to the research published in the journal Nature Communications.

The team developed a way to 3D print neural probes and other electronic devices that are as soft and flexible as rubber.

The devices are made from a type of polymer, or soft plastic, that is electrically conductive.

The team transformed this normally liquid-like conducting polymer solution into a substance more like viscous toothpaste -- which they could then feed through a conventional 3D printer to make stable, electrically conductive patterns.

The team printed several soft electronic devices, including a small, rubbery electrode, which they implanted in the brain of a mouse.

As the mouse moved freely in a controlled environment, the neural probe was able to pick up on the activity from a single neuron. Monitoring this activity can give scientists a higher-resolution picture of the brain's activity, and can help in tailoring therapies and long-term brain implants for a variety of neurological disorders.

"We hope by demonstrating this proof of concept, people can use this technology to make different devices, quickly," said Hyunwoo Yuk, a graduate student at Massachusetts Institute of Technology (MIT) in the US.

"They can change the design, run the printing code, and generate a new design in 30 minutes. Hopefully this will streamline the development of neural interfaces, fully made of soft materials," Yuk said.