Want to skip wearing your Fitbit or Jawbone when you’re out for a run or hitting spin class?
More importantly, think one day that people with epilepsy could live symptom free or a paraplegic could walk again? Or a soldier who’s lost a leg could control a robotic limb with his thoughts?
All of those cases could happen because scientists are developing sensors the size of dust particles that would work inside the body to keep track of how much we’re exercising, to stimulate the brain or muscles, or to monitor how certain organs are working.
Engineers at the University of California, Berkeley, have built dust-sized, wireless sensors that could be implanted in the human body, monitoring everything from muscles to nerves and organs.
The sensors, which have been dubbed "neural dust," have been implanted in the muscles and peripheral nerves of rats, but scientists already believe they could be used to stimulate muscles and nerves, possibly treating inflammation or epilepsy.
“I think the long-term prospects for neural dust are not only within nerves and the brain, but much broader,“ said Michel Maharbiz, an associate professor of electrical engineering and computer sciences at UC Berkeley, in a statement. “Having access to in-body telemetry has never been possible because there has been no way to put something super tiny super deep. But now I can take a speck of nothing and park it next to a nerve or organ, your GI tract or a muscle, and read out the data.“
According to the university, the sensors fit into a 1 millimeter cube, which is about the size of a grain of sand.
However, researchers are working to shrink them down even smaller, down to a cube of 50 microns per side. That’s about 2 thousandths of an inch, or half the width of a human hair.
Once the sensors are that small, researchers say they could be implanted inside the brain, as well as in muscles or nerves.
The sensors would be powered by a piezoelectric crystal, which can convert ultrasound vibrations outside the body into electricity that is used to run the sensor’s onboard transistor.
Piezoelectricity is the charge that builds up in certain solid materials, such as bone, DNA and crystals, because of applied mechanical stress.
In lab tests, so far, the sensors have been covered in surgical-grade epoxy. However, scientists are working on what they call "biocompatible thin films," which could one day cover the sensors and last as long as a decade inside the body.
“The original goal of the neural dust project was to imagine the next generation of brain-machine interfaces, and to make it a viable clinical technology,” said UC Berkeley neuroscience graduate student Ryan Neely, in a statement. “If a paraplegic wants to control a computer or a robotic arm, you would just implant this electrode in the brain and it would last essentially a lifetime.”