Researchers develop new smart textiles

Zurich, Switzerland – 18 May, 2025 – New smart textiles developed by researchers at ETH Zurich rely on acoustic waves and glass fibres to enable precise measurements. They are lightweight, breathable and cost-effective and offer great potential for medicine, sports and everyday life.

Imagine you're wearing a T-shirt that measures your breathing rate, or gloves that translate your hand movements into commands for the computer. Researchers at ETH Zurich led by Daniel Ahmed, Professor of Acoustic Robotics for Life Sciences and Public Health, have laid the foundations for such smart textiles. Unlike many previous developments in this field, which mostly use electronics for this purpose, the ETH researchers rely on acoustic waves that are conducted through glass fibres. This makes the measurements more precise and the textiles lighter and more breathable and easier to wash. "They are also cost-effective because we use easily accessible material, and the electricity consumption is very low," says Ahmed.

Acoustic sensors in the fabric
The researchers call their development sono-textiles. In the process, they transformed normal fabrics into smart sensors that react to touch, pressure and movements. "There has already been research on acoustic-based smart textiles, but we are the first to test optical fibers in combination with signals that use different frequencies," explains Yingqiang Wang, first author of the study published in the journal Nature Electronics published study.

The researchers have woven glass fibers through the fabric at regular intervals. At one end of it is a small transmitter that emits sound waves. The other end of all optical fibers feeds into a receiver that measures whether the waves have changed.

Each transmitter works with a different frequency. In this way, it is possible to detect on which fiber optic cable the sound waves have changed with little computing power. Previous smart textiles often struggled with problems of data overload and signal processing, as each sensor point had to be evaluated individually. "In the future, the data could be sent directly to a computer or smartphone in real time," says Ahmed.

When a glass fiber is moved, the length of the acoustic waves flowing through it changes as they lose energy. In the case of a T-shirt, this can happen through body movement or breathing. "We used frequencies around 100 kilohertz in the ultrasonic range – far outside the human hearing range, which is between 20 hertz and 20 kilohertz," Wang emphasizes.

Versatile use
The researchers have shown in the laboratory that their concept works. In the future, Sono textiles could be used in various areas: As a shirt or T-shirt, they could monitor the breathing of asthma patients and warn in an emergency.

In sports training and performance monitoring, athletes could receive real-time analysis of their movements to optimize their performance and prevent injuries. The textiles also offer potential for sign language: gloves with this technology could simultaneously translate hand movements into text or speech. They could also be used in virtual or augmented reality environments.

"Sono-textiles could even measure a person's posture and, as an assistive technology, improve quality of life," adds Chaochao Sun, who is also first author of the study. People who want to improve their posture could thus receive targeted feedback to correct poor posture. Even in wheelchairs, the textiles could indicate when relocation is necessary to prevent pressure ulcers.

Even though the suitability of the Sono textiles for everyday use is potentially very high, Ahmed adds that there is still room for improvement in terms of practical application. Glass fibers as sound conductors were ideal in the laboratory, but in everyday life they can potentially break. "The nice thing is that we can easily replace the glass fibers with metal. Sound also propagates effectively through metal," explains Ahmed, adding: "We would like to expand our research in this direction and also to other applications." Next, the researchers want to make the system more robust and test how the electronics can be better integrated into the textiles.