NEW YORK (Reuters Health) – Researchers have developed a wireless, battery-free, skin-mounted sensor that can detect vaporized nicotine, such as that given off by e-cigarettes.
E-cigarettes are designed to heat and thus aerosolize a mixture of ingredients that includes nicotine, whose health hazards have long been recognized, the researchers note in ACS Sensors. They add that the lack of a suitable method for detecting nicotine vapor makes it difficult to control “the alarming growth” of e-cigarette use by high school students in the United States, which went from 1.5% in 2011 to 16% in 2015.
The new nicotine sensor measures 11 mm by 26 mm, Dr. Madhu Bhaskaran of RMIT University, in Melbourne, Australia, told Reuters Health by email. A photo in the report shows the sensor on the back of an individual’s hand.
There are several potential markets for the nicotine sensor, Dr. Bhaskaran said, including secondary schools, to monitor vaping among students; individuals with chronic illnesses, to monitor their exposure to secondhand smoke; and patients with lung diseases such as chronic obstructive pulmonary disease, who could use the device to avoid areas where vaping or smoking are taking place.
The device uses a thin film of vanadium dioxide on a polyimide substrate. Nicotine bonds covalently to this film, altering the its conductivity. The device detects that change, which depends on nicotine concentration; amplifies the resulting signal; and sends the signal wirelessly to a smartphone.
The wireless transmission is by way of a near-field communication (NFC) interface, a very-short-range (1-2 inches) communications technology that’s used in contactless credit cards and also provides for wireless power delivery. Dr. Bhaskaran noted that if needed, the design could be tweaked by replacing NFC with Bluetooth for longer-range operation.
She added that the device could be configured not as wearable, but as a “nearable,” that is, as a smart object that collects information relevant to you without your having to wear it.
“The device selectively detects nicotine in the environment,” Dr. Bhaskaran noted, which the research team established by testing across various environmental gases, such as CO, H2, CH4, H2S, and NO2.
The current version, with NFC, “will cost a couple of dollars if mass produced,” she estimated.
Dr. Ali Javey, professor of electrical engineering and computer sciences at the University of California at Berkeley and co-director of the Berkeley Sensor and Actuator Center, told Reuters Health that there “is significant interest” in examining the nicotine exposure of various groups, including those exposed to secondhand smoke.
“In this regard, development of noninvasive sensors that can provide real-time information on nicotine exposure levels is of utmost interest,” he said by email.
Dr. Javey cautioned, however, that “a common challenge with chemoresistive sensors used in this work is selectivity against other chemicals and changes in ambient conditions, such as temperature and humidity. While the preliminary results presented in this work look promising, significant future work needs to be done to systematically study the selectivity, stability, and sensitivity of the sensors in various relevant environments to prove their viability for practical use.”
In an email to Reuters Health, Dr. Monika Singh of the Institute of Nano Science and Technology, in Mohali, India, called this research “very commendable” and the battery-free wireless technology “remarkable and quite handy.”
“Nicotine-sensing devices provide an easy way to find out the presence of second-hand smoke in air,” she continued. Such sensors “will certainly help to have a regular check on air quality, specifically sensitive areas like hospitals, schools, residential areas, airports, etc.”
Neither Dr. Javey nor Dr. Singh, both of whom have researched nicotine sensors, was involved with the new work.
The research was funded by the Australian Research Council. The authors declared no conflicts of interest.
SOURCE: https://bit.ly/3lWOPsA ACS Sensors, online December 8, 2021.