Tired From Work? This Smart Sportswear Can Tell if You’re Exhausted via "Electronic Yarn"

Are you tired from work? Or has your body reached its limit during workouts? Do you wish you had a way to monitor your fatigue levels without having to constantly check in with your body?

Well, ETH Zurich researchers have got you covered with their new invention: smart leggings equipped with a textile sensor that measures your exhaustion in real time!

Special Yarn

Led by Professor Carlo Menon, Head of the Biomedical and Mobile Health Technology Lab, the team has created a stretchable sensor that is integrated directly into the material fibers of the leggings.

No more bulky electronic components retrofitted to your clothes, no more high prices, and no more complicated maintenance. It is as easy as slipping on a pair of leggings and glancing at your smartphone.

But how does it work? The special yarn used in the sensor has an inner fiber made of conductive, elastic rubber, with a rigid wire wrapped around it in a spiral. The two fibers act as electrodes and create an electric field, forming a capacitor that can hold an electric charge.

When worn, the leggings stretch and slacken at a certain rhythm as the wearer runs, altering the gap between the two fibers, the electric field, and the capacitor's charge.

These charge fluctuations are too small to measure under normal circumstances, but the yarn becomes thicker when stretched, making it considerably more sensitive to minimal movements.

Stretching it even a little produces distinctly measurable fluctuations in the sensor's charge, making it possible to measure and analyze even subtle changes in running form.

The sensor has been tested on a group of runners wearing similar leggings equipped with the same sensor, and the electric signals were recorded as the runners became more and more tired.

These signals were then used to create a model capable of predicting runners' exhaustion levels, which can now be used for the textile sensor. However, further testing and data collection will be necessary to ensure that the model can make accurate predictions outside of the lab.

Wireless Sending of Electric Signals

To enable the textile sensor to send electrical signals wirelessly to a smartphone, the researchers equipped it with a loop antenna made of conducting yarn, sewn directly onto the leggings.

The sensor and antenna form an electrical circuit that is fully integrated into the leggings, and the electrical signal travels from the sensor to the antenna, which transmits it at a certain frequency capable of being read by a smartphone.

The wearer runs and the sensor moves, creating a signal pattern with a continuously fluctuating frequency, which a smartphone app then records and evaluates in real time.

The researchers are now working on turning their prototype into a market-ready product, to make the manufacture of smart clothing cost-effective and thus available to a broader public.

The work of the team was further detailed in Advanced Materials.