Last updated on December 8th, 2022 at 02:09 pm
A new system based on silicon chips allows you to monitor hundreds of neurons in the brain in real time.
Researchers at Stanford University have developed a new device for directly connecting the brain to silicon-based computers. The brain-computer interface devices have existed for a relatively long time and are used for prosthetics, treatment of certain diseases, and studies of brain signals. However, a new development, data on which appeared on March 20 in the journal Science Advances, is able to read more data, being less invasive than the existing options.
“Nobody before us took two-dimensional silicon electronics and docked it with the three-dimensional architecture of the brain,” says a post-graduate student at the Department of Materials Science and Engineering at Stanford and one of the participants in the study, Abdulmalik Obaid. According to him, scientists had to not take into account what is already known about the traditional manufacture of microcircuits, and develop new processes for silicon electronics to work with three-dimensional architecture.
The upper part of the array with microwires. Using a silicon chip attached to the upper end and wires at the bottom that is neatly inserted into the brain, the new device will help you record a video about the activity of neurons. Image: Andrew Brodhead
The new development includes a bundle of microwires, each of which is twice as thin as human hair. These wires are carefully implanted into the brain and connected externally directly to the silicon microcircuit. She, in turn, records the electrical signals of the brain in the form of a film about the electrical neural activity.
“Electrical activity is one of the most accurate ways to measure brain activity. And with this set of microwires, we can see what happens at the level of single neurons, ”says one of the co-authors of the development, Nick Melosh, a professor of materials science and engineering at Stanford.
One of the main tasks that the researchers faced was to figure out how to structure the array of wires. It had to be strong and durable, although its main components are hundreds of tiny cables. The solution was found: it was necessary to wrap each wire in a biologically safe polymer, and then tie all the cables together into a metal clamp. This ensures that the wires are correctly spaced and oriented. There is no polymer below the collar, and the wires can connect to the brain.
Abdulmalik Obeid (left) and Nick Melosh with his invention. This bundle of microwires will allow researchers to monitor the activity of hundreds of neurons in the brain in real-time. Image: Andrew Brodhead
Existing brain-computer interface devices are limited to approximately a hundred wires — these are 100 channels for signal transmission. The new device is an array with thousands of channels, making it possible to record signals from different areas of the brain at different depths.
The new device was tested on the brains of living rats and mice. In both cases, scientists successfully received signals. Now the task of researchers is to find out how long the system can remain in the brain and what other data it can get.
The authors of the project are especially interested in signals from the brain that are transmitted in the learning process. They also expect that the development will turn out to be used in prosthetics and for devices that help restore speech and vision. In the meantime, long-term animal tests are ongoing to test the durability of the array and the performance of scaled versions of the invention.