Engineering news
Researchers at the University of California, San Diego developed the chip, which is small enough to be implanted below the surface of the skin, and is wirelessly powered by a wearable device.
“The ultimate goal of this work is to develop a routine, unobtrusive alcohol and drug monitoring device for patients in substance abuse treatment programmes,” said Drew Hall, an electrical engineering professor in the university's Jacobs School of Engineering, who led the project.
Breathalysers are the most common form of monitoring for people in alcohol treatment programmes, but they are clunky devices that require the patient to initiate a test, and, as Hall noted, they’re not that accurate.
Blood tests provide more precision, but need to be conducted by a trained technician. And, while tattoo-based alcohol sensors are a new technology that is showing promise, they are easy to remove and single-use only.
“A 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,” Hall said.
The chip is one cubic millimetre in size, and can be injected into the interstitial fluid, which surrounds the cells of the body. It contains a sensor coated in alcohol oxidase, an enzyme that interacts with alcohol to create a substance that can be detected electrochemically.
The chip is powered by a wearable device such as a smartwatch, and is designed to use as little power as possible. It currently uses a total of 970 watts, or about one million times less power than a smartphone making a call.
The chip is being tested in the lab, and in future it could be adapted for use with other substances. “This is a proof-of-concept platform technology. We’ve shown that this chip can work for alcohol, but we envision creating others that can detect different substances of abuse and injecting a customised cocktail of them into a patient to provide long-term, personalised medical monitoring,” Hall said.