Fitbit is starting to seem a little quaint. The sensors of the future will be dust-sized, wireless, implanted deep in the body, and have the potential to robotically control a prosthetic arm or leg or treat diseases like epilepsy.
Researchers at the University of California-Berkeley recently demonstrated that their "neural dust"—wireless sensors that are currently about the size of a grain of sand—can be implanted next to nerves and then powered by an ultrasonic patch on the skin. Ultrasound can also be used to continuously read data from inside the body.
For someone who's paralyzed, the device could eventually be used to run a brain-machine interface to help them move prosthetics. Right now, some similar technology uses implantable electrodes that can only last a couple of years. Patients also have to have wires running through a hole drilled in their skull—both awkward and a potential risk of infection. The new devices could potentially last a lifetime.
"The work addresses this really long-standing and complex problem in the field, which is that neural interfaces don't last for decades inside people at the moment," says Michel Maharbiz, an associate professor of electrical engineering and computer sciences and one of the lead researchers on the project. "Nobody has the solution for that. Our approach to make them really small and wireless in this way is sort of one part of this whole more complex problem."
The tiny new devices could pull information from the brain, and then the data could help a paralyzed person to use an exoskeleton or artificial limbs. The researchers are working on a new version of the neural dust that can also stimulate nerves, which could be used to control disorders like incontinence or epilepsy.
"Many versions of those conditions are caused by not being able to fire the nerve right," says Maharbiz. "So if you can take data at the right place and then stimulate it you can really build some pretty interesting therapies."
Eventually, the devices could be used anywhere in the body, measuring, for example, oxygen rates and pH levels next to organs—something that isn't possible to do continuously now. "The truth is there is no platform that allows you to take data from deep within the body in a way that potentially would be chronic the way this would be," he says. "This would be so small that you could endoscopically park it next to something and be done, basically. And then just talk to it from the outside."
The researchers are working on making the tiny motes even smaller; to work in the brain, they will need to be about half the width of a human hair.
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