'Smart' fabrics with integrated biosensors that monitor respiratory rate and body temperature in real time
According to an article published this month on ScienceDaily.com, using an organic semiconductor, electrical engineering researchers at the University of Arkansas have manufactured and tested two similar, although slightly different, biosensors. Integrated into “smart” fabrics –clothing with wireless technology–, the sensors will be able to monitor the respiratory rhythm and body temperature of a patient in real time, which will allow health professionals to carry out on-site diagnoses and give patients greater freedom. patients.
"We try to bring diagnostic tests out of the lab, right to where the patient is," says Taeksoo Ji, an assistant professor of electrical engineering. “Although there have been some successes in connection with this initiative in the last ten years, traditional materials are not enough to make high-range, low-cost sensors. The advantages of organic semiconductors will allow manufacturers to produce lightweight, flexible devices that can be easily integrated into biomedical applications such as smart vests and fabrics. "
Researchers Ji and Soyoun Jung, a graduate student in electrical engineering under the direction of Vijay Varadan, Distinguished Professor in electrical engineering, worked with pentacene (a hydrocarbon molecule) and carbon nanotubes to develop the two types of sensors: one of temperature and another of effort. The addition of carbon nanotubes to the pentacene increases the sensitivity of the sensors. As an organic semiconductor, pentacene is efficient and easy to control. The two sensors were fabricated directly on flexible polymeric substrates.
The effort sensor, which monitors the respiratory rate, consists of a Wheatstone bridge, an instrument that measures unknown electrical resistances, and the thin sheet of pentacene that acts as a detection layer. The system works when a physiological effort, such as respiration, causes a mechanical deformation of the sensor, which affects the resistance of the electric current. The researchers observed that the smaller the sensor, the more sensitive it was to current variations.
As for the temperature sensor, the researchers used what is known as a thin-film transistor, a special type of transistor that deposits thin-film semiconductors on substrates. The thin-film transistor allowed the researchers to observe electrical current in linear response to changes in temperature. And most importantly: it was in the areas of lower voltages where the current showed greater sensitivity to changes in temperature.
The success of this research is promising for patients whose vital signs need to be continuously monitored. According to Varadan, the sensors and wireless networks can be integrated into clothing items, such as underwear shirts. With this technology, the smart tissue can monitor vital signs and collect and send the data to a central information station in real time. From this information, any physiological abnormality can be detected immediately, allowing doctors to start treatment or prevent diseases before problems reach an acute state.
Source: Science Daily