Researchers at Harvard and Beijing’s National Center for Nanoscience and Technology have developed a method of using a needle measuring just a few millimeters in length to inject mesh electronics directly into the brain.
As John Wenz of PopularMechanics explains, this technique allows the mesh to safely unfurl, providing a non-invasive way to deploy sensors and electronic brain-stimulating devices.
“The invention, published in Nature Nanotechnology, could open up a new frontier in cybernetic electronics,” writes Wenz.
Image Credit: Harvard Gazette
“Such injected electronics could be used in brain monitors for patients with epilepsy, brain-computer interfaces for smart prosthetics, spinal cord connective tissue repair and in monitoring heart arrhythmia.”
However, says Wenz, brain biopsies, at least in the short term, stand to gain the most from the technique.
“Rather than having to open the entire skull case (or a portion of it), a near-microscopic hole is drilled through the skull, then the needle is inserted to deploy the mesh electronics,” he adds. “So far, the treatment has only been tested on mice, but the researchers believe that, once approved on humans, it could be performed as an outpatient procedure—no hospitalization required.”
Commenting on the above-mentioned report, Rambus Fellow Dr. David G. Stork notes that microelectronic circuits can be packaged a number of ways. Indeed, flat silicon chips are the most common, appearing in every computer, smart phone and digital camera. Most recently, however, circuits have been created on flexible substrates, like plastic sheets, in order to design flexible or curved displays, or to be placed on the skin and other curved surfaces.
“Now the large Harvard – Chinese Center for Nanoscience and Technology team has demonstrated a new form of structure: the flexible or ‘macro-porous’ mesh,” Dr. Stork told Rambus Press during a recent interview in Sunnyvale. “Imagine a fishing net where the rope is replaced by flexible polymer/metal wires and the rope knots are replaced by electronic devices such as sensors, microprocessors and so on. Now imagine this net, fully spread, is roughly just one cm across and can be bundled up so small that it can fit into a hypodermic needle and injected.”
Perhaps the most intriguing aspect of the research, says Stork, is how the team injected an electronic mesh into the cortex of live rodents – with the mesh’s slight stiffness enabling the net to expand outwards and envelop a small volume of the brain.
“With clever design of the stiffness of the polymer wires, the researchers could ultimately control the shape of the final mesh in the brain,” Stork explains. “For example, if the wires are stiff in the up-down direction but floppy in the left-right direction, then the final shape will be a cylindrical tube. Nanoelectrodes in the mesh monitor the activity of neurons in the living rodent brain.”
As Dr. Stork emphasizes, there is still much work to be done before meshes are safely and successfully implanted into human brains.
“Nevertheless, perhaps someday such mesh electronics could be injected into patients with neurological diseases to monitor brain activity and even provide routine therapy,” he adds.