Flex on the Brain: The Future of Neural Interfaces

Estimated reading time: 2 minutes

The SMTA Additive Electronics TechXchange took place virtually on October 14, with presentations from a wide variety of technologists involved in additive processes. Organizers Tara Dunn of Omni PCB and Lenora Clark of ESI Automotive did a great job putting together this event.

One of the highlights was a presentation titled “Flexible Electronics for Neural Interfaces” by Dr. Jonathan Viventi, assistant professor of biomedical engineering at Duke University. His research with flexible electronics has helped create new types of technology for interfacing directly with the human brain, allowing high-resolution scans over wide areas. This technology can diagnose and treat all kinds of neurological disorders, including epilepsy.

In a fascinating presentation, Viventi explained that earlier brain sensors were impractical, often using thousands of electrodes, and they offered only two options: a high-resolution scan of a small part of the brain or a low-resolution shot of a broad area.

Now, Viventi’s new flexible silicon interface fits directly onto the brain and can provide a high-res look at a wide area. He noted that silicon could behave just like a flexible circuit if you make it thin enough. In his research at Duke, Viventi has investigated the use of LCP and polyimide, both of which use additive processes, and they’re fairly inexpensive as well.

His interface has been tested and found to be safe on rats and monkeys. Now, humans having brain surgery can volunteer to have one placed on their brain and removed when surgery is completed. Viventi explained that placing the flexible silicon on the brain isn’t too dangerous.

“The brain is actually pretty tough,” Viventi said. Doctors induce a seizure with drugs, and they’re able to detect waves propagating through the brain that they were missing before. Previous tools just didn’t have high enough resolution.

Interestingly, the human subject stays awake during the brain scan. Viventi said the doctors ask patients to answer questions during the procedure. I don’t know if I’d like that part, but I see the point. Viventi said plans are underway to scale up to commercial CMOS silicon; each of these interfaces would replace 65,000 electrodes.

LCP interfaces are especially robust, with accelerated aging showed that they would last more than five years at 37°C, and they offer great biocompatibility. Viventi’s research is a great reminder of how technology is being used to save lives and treat neurological disorders every day.