Patients in substance abuse treatment programs.


One of the challenges for patients in treatment programs is the lack of convenient tools for routine monitoring. Breathalyzers, currently the most common way to estimate blood alcohol levels, require patient initiation and are not that accurate. A blood test is accurate, but it needs to be performed by a trained technician. The miniature, ultra-low-power, injectable biosensor could be used for continuous, long-term alcohol monitoring. The chip is small enough to be implanted in the body just beneath the surface of the skin, and is powered wirelessly by a wearable device such as a smartwatch or patch. The biosensor chip measures roughly one cubic millimeter in size and can be injected under the skin in interstitial fluid — the fluid that surrounds the body's cells. It contains a sensor that is coated with alcohol oxidase, an enzyme that selectively interacts with alcohol to generate a byproduct that can be electrochemically detected. The electrical signals are transmitted wirelessly to a nearby wearable device such as a smartwatch, which also wirelessly powers the chip.

The alcohol monitoring chip is small enough to be implanted just under the surface of the skin. (David Baillot/UCSD Jacobs School of Engineering)
The chip compared to the thickness of a penny. (David Baillot/UCSD Jacobs School of Engineering)


Jacobs School of Engineering, University of California, San Diego


The patent-pending technology is available for licensing.


The tiny injectable sensor that can be administered in a clinic without surgery could make it easier for patients to follow a prescribed course of monitoring for extended periods of time.