New textile sensor measures exhaustion

In the future, smart sportswear and workwear could potentially alert wearers to the onset of exhaustion and, in so doing, help to prevent fatigue-related injuries. To make this vision a reality, a textile sensor integrated into a tight-fitting, elastic piece of clothing would be needed. However, electronic components are not necessary, which helps to simplify production and cut costs, in addition to making product maintenance easier.

According to a press release issued by the Swiss Federal Institute of Technology in Zurich (ETH), this new textile sensor was developed by one of its research teams. It provides real-time data on how exhausted a person feels during physical exertion. To test the new sensor, the team integrated it in a pair of athletic leggings. “Our goal is to make the manufacture of smart clothing cost-​effective and thus make it available to a broader public”, comments Carlo Menon, Head of the Biomedical and Mobile Health Technology Lab at ETH Zurich and scientific director of the study, in the press release.

The sensor registers how movements change when physical fatigue begins using a special yarn made of two fibers, which “act as electrodes and create an electric field”, explains Tyler Cuthbert, a postdoctoral student in Menon’s research group. Together they form a capacitor. With every movement, the gap between the two fibers changes, and thus also the electric field and the capacitor’s charge.

An antenna, which is directly sewn onto the leggings in the form of a loop, receives the electrical signal from the stretchable sensor and in turn emits a signal that can be read by a smartphone. According to ETH Zurich, the test subjects were able to simply glance at their smartphone to see when they were starting to reach their limit and should take a break. However, the press release also goes on to say that development and refinement work is still necessary before an app can record and evaluate a signal pattern in real time. mm