Perspiration is basically sweating from sweat glands, often in response to heat, exercise or stress. Researchers have developed a fitness sensor that monitors the sweat of a person and keeps a check on their health.
The study was published in the journal, ‘Small Methods’. Ultrathin nanomaterials, known as MXenes, are poised to make it easier to monitor a person’s well-being by analysing their perspiration.
While they share a similar two-dimensional nature to graphene, MXenes are composed of non-toxic metals, such as titanium, in combination with carbon or nitrogen atoms. With naturally high conductivity and strong surface charges, MXenes are attractive candidates for biosensors that can detect small changes to chemical concentrations.
In 2019, Husam Alshareef’s group developed an MXene composite electrode, which they enclosed in a wearable armband sensor. The device, which had a modular design that used MXene inserts loaded with appropriate enzymes, could absorb perspiration and detect several analyses in human sweat, including glucose and lactic acid.
Alshareef and his colleagues, in collaboration with Sahika Inal’s research team, recently tried combining MXene sheets with hydrogels — water-filled polymers that are compatible with human tissue because they are able to stretch. Intriguingly, the team found that high levels of mobile ions in the hydrogel produced strong sensitivity to the mechanical strain that occurs during exercise.
“Initially the MXene sheets are randomly oriented within the hydrogel, but once you apply pressure to them, the sheets become more horizontally oriented,” explained Alshareef. “Because MXenes have a high concentration of negative charges on their surfaces, horizontal arrangements strongly affects ion movements within the hydrogel, and thus we can measure different levels of pressure change.”