Scientists from Stanford University have created a new device that connects the brain straight to silicon-based technologies.
Although brain-machine interface devices are already in use, employed for prosthetics, disease treatment, and brain research, this new device is able to register more information even though it is less intrusive than existing options.
“Nobody has taken these 2D silicon electronics and matched them to the three-dimensional architecture of the brain before,” said Abdulmalik Obaid, a graduate student in materials science and engineering at Stanford. “We had to throw out what we already know about conventional chip fabrication and design new processes to bring silicon electronics into the third dimension. And we had to do it in a way that could scale up easily.”
The Goal is to Improve Medical Technologies
The new device features a handful of microwires, with each of them less than half the width of the thinnest human hair. These wires can be introduced into the brain and connected on the exterior straight to a silicon chip that registers the electrical brain signals traveling through each wire. Current versions of the technology only pack hundreds of microwires, but advanced models could contain thousands.
“Electrical activity is one of the highest-resolution ways of looking at brain activity,” said Nick Melosh, professor of materials science and engineering at Stanford and co-senior author of the study. “With this microwire array, we can see what’s happening on the single-neuron level.”
The team of scientists tested their brain-machine device on isolated retinal cells from rats and in brains of alive mice. They successfully gathered important signals across the network’s channels in both cases.
The researchers are currently working on applications in prosthetics, in particular speech assistance. They knew that to achieve their goals, they had to develop a brain-machine interface that was long-lasting, and also able to create a close connection with the brain while producing less damage.
“Silicon chips are so powerful and have an incredible ability to scale up,” said Melosh. “Our array couples with that technology very simply. You can actually just take the chip, press it onto the exposed end of the bundle and get the signals.”
Years of Work Finally Paid Off
One main difficulty the scientists encountered was deciding how to structure the network of wires. Current brain-machine interface devices are only featuring about 100 wires, providing 100 channels of signal, and each has to be meticulously placed in the network manually.
The team spent years refining their design and manufacturing techniques in order to provide with the creation of a network with thousands of channels.
“The design of this device is completely different from any existing high-density recording devices, and the shape, size, and density of the array can be simply varied during fabrication. This means that we can simultaneously record different brain regions at different depths with virtually any 3D arrangement,” said Jun Ding, assistant professor of neurosurgery and neurology, and co-author of the research. “If applied broadly, this technology will greatly excel our understanding of brain function in health and disease states.”
After spending years to achieve this ambitious aim, they finally came up with a device that could be tested in living tissue. The team of researchers is optimistic about being able to use the network in the future in order to enhance medical technologies for people.