Skin-worn sensor detects and measures nicotine in e-cig vapor
Nicotine is one of the more harmful compounds in the vapor produced by electronic cigarettes, so non-vapers should avoid breathing it in whenever possible. A new skin-worn sensor could help, by monitoring airborne nicotine levels in the wearer's immediate vicinity.
Developed by scientists from the University of Arizona and Australia's RMIT University, the prototype battery-free device gets temporarily adhered to the skin on an exposed part of the user's body, such as the back of their hand.
Among other things, it incorporates an NFC (near-field communication) chip, a loop coil for wireless power transfer, and the actual nicotine sensor itself. The latter consists of a polyimide plastic substrate, covered with a thin film of an inorganic compound known as vanadium dioxide (VO2). Any aerosolized nicotine molecules that are present in the air passing over the sensor will bond with the VO2, altering its electrical conductivity.
An NFC-capable device such as a smartphone is able to wirelessly power up the sensor, allowing an electrical current to be run through the VO2 film. Conductivity readings are transmitted back to the phone, which analyzes them to determine airborne nicotine levels – the greater the number of nicotine molecules that bond with the VO2, the greater the change in conductivity.
U Arizona's Dr. Philipp Gutruf – who is leading the study along with RMIT's Prof. Madhu Bhaskaran and Dr. Ataur Rahman – tells us that the technology could also be used to detect nicotine in traditional cigarette smoke, although extra sensors would be necessary due to the additional gases and solids which are emitted when smoking.
A paper on the research was recently published in the journal ACS Sensors.