Dartmouth Engineering Professor Co-authors Protocol for Creating Bioelectronic Neural Implants

Thin-film, bioelectronic device constructed at Dartmouth's Regenerative Bioelectronics Lab using the protocol. (Photo courtesy of PhD Innovation Program student, Jonathan Pelusi.)

"For someone running a neuroscience lab, for example, who wants to record brain activity down to the single neuron scale but doesn't know how, they can pull this paper up and follow the protocol to make a device and implement it surgically," said co-author Alexander Boys, an assistant professor of engineering at Dartmouth. Boys helped establish the protocol while transitioning to Dartmouth from his postdoctoral fellowship in Professor George Malliaras' lab at the University of Cambridge.

The paper titled, "Fabrication of thin-film electrodes and organic electrochemical transistors for neural implants," lays out the method for anyone to build and implement a bioelectronic neural interface in their lab. "At Dartmouth, we're working with these devices right now," said Boys. "So, in this study, I detail a number of different surgeries you can do. You can build a whole circuit off of a protocol like this to insert into a body." 

The devices are designed to have minimal impact once they're placed within living tissue. "They're very light and only a few microns thick, so a tenth to a hundredth of a human hair in thickness," explained Boys. The actual recording sites of the microelectrodes are single-cell size.

The small scale of the electronics opens new possibilities for studying the peripheral nervous system which has so far been challenging. "As you move off from your spinal cord, you get into the fractal elements of your nervous system," said Boys, "and by the time you get to the sensory innervation of your toes, it's down to just one cell."

With devices at this scale that sit comfortably in tissue, researchers can interact precisely with all aspects of the nervous system.

"And that's never really been done before," added Boys. "You can just make one up to do exactly what you want it to do, and that's the power of it. And the actual properties are substantially better than the clinical versions right now."

In addition to a project that's investigating the gut-brain axis, Boys' Regenerative Bioelectronics Lab is using the same devices to study pain management. 

"We're working on building an implant right now to record pain," said Boys. "For accessing pain signals, we need sufficient contact with the tissue without causing a huge foreign body response. Then, theoretically, we can actually shut down the pain response with stimulating electrodes. So, we're designing the same implants to work on that problem.

"It's pretty cool. I think it's a really exciting area to be in."