The device known as StimDust is short for stimulating neural dust, and can add more electronics without losing its small size. The goal for this device is to be able to implant StimDust into the body, with a small procedure, to monitor and treat disease with a patient-specific approach.
StimDust’s size is that of a granule of sand, measuring 6.5 cubic millimeters in volume. The wireless device is powered by ultrasound, where StimDust uses power nerve stimulation with 82 percent efficiency.
“StimDust is the smallest deep-tissue stimulator that we are aware of that’s capable of stimulating almost all of the major therapeutic targets in the peripheral nervous system,” said Rikky Muller, co-lead of the work and assistant professor of electrical engineering and computer sciences at Berkeley, according to Berkeley News. “This device represents our vision of having tiny devices that can be implanted in minimally invasive ways to modulate or stimulate the peripheral nervous system, which has been shown to be efficacious in treating a number of diseases.”
StimDust includes a single piezocrystal, which acts as the antenna, a 1-millimeter integrated circuit and a charge storage capacitor. The electrodes on the bottom of the device create contact with a nerve through a cuff; this cuff wraps around the actual nerve. The team also designed a custom wireless protocol that allows for a range of efficient programmability. The device is powered by four microwatts.
The research team tested the device in a live rodent for more realistic conditions. With the cuff around the sciatic nerve, the team could control hind leg motion, record stimulation and activity, and measure the force exerted on the hind leg muscles.
Eventually, they hope this work can allow StimDust to treat diseases like heart irregularities, chronic pain, asthma or epilepsy.
This miniscule device has created an opportunity for wireless communication to the brain and peripheral nervous system. Now, engineers worldwide are using neural dust to build implantable devices powered by ultrasound.
“One of the big visions of my group is to create these very efficient bidirectional interfaces with the nervous system and couple that with intelligence to really understand the signals of disease and then to be able to treat disease in an intelligent, methodical way,” said Mueller, according to Berkeley News. “There’s an incredible opportunity for healthcare applications that can really be transformative.”
To delve into the components of this little device, view the StimDust in action here.
Feature Photo Credit: The tiny size of StimDust is obvious when placed on the face of a dime. StimDust is about an order of magnitude smaller than any known active device with similar capabilities. Click to expand. (Photo courtesy of Rikky Muller)