Standard brain implants use electrodes that penetrate the gray matter to stimulate and record neuronal activity. They usually need to be installed through a surgical procedure. To circumvent this need, a team of researchers led by Deblina Sarkar, an electrical engineer and assistant professor at the Massachusetts Institute of Technology, developed microscopic electronic devices hybridized with living cells. These cells can be injected into the circulatory system using a standard syringe and will travel through the bloodstream before being implanted in targeted areas of the brain.
“In the first two years of working on this technology at MIT, we received 35 consecutive rejected grant applications,” says Sarkar. “The comments we received from reviewers were that our idea was very effective, but it was not possible.” She admits the sentence sounded like something you'd find in a science fiction novel. But after more than six years of research, she and her colleagues succeeded.
Name the problems
In 2022, after Sarkar and her colleagues had collected initial data and seen some promising results with their cell electronics hybrids, the team proposed the project for the National Institutes of Health Director's New Innovator Award. For the first time after 35 refusals, it passed expert evaluation. “We got the highest score ever,” says Sarkar.
The reason for this rating was that its technology solved three extremely difficult problems. The first, obviously, was to create functional electronic devices smaller than cells that could circulate in our blood.
“Previous studies, which had little success, relied on placing magnetic particles in the bloodstream and then guiding them using magnetic fields,” explains Sarkar. “But there is a difference between electronics and particles.” Electronics made using CMOS technology (which we use to create computer processors) can generate electricity from incident light in the same way as photovoltaic devices, as well as perform the calculations needed for smarter applications such as touch control. Particles, on the other hand, can only be used for specific cell stimulation.
