Flexible fibre sensor paves the way for truly smart textiles

Smart textile technology developed by a research group in Switzerland could be used to develop everything from intelligent clothing to hospital bed sheets able to monitor a patient’s movements.  

fibre sensor
Researchers have developed electronic fibres that, when embedded in textiles, can be used to collect data about our bodies by measuring fabric deformation. Image: EPFL

Developed by a team at EPFL in Lausanne, the innovation is based on a specially developed sensor that can simultaneously detect different kinds of fabric deformation like stretching, pressure and torque.

The flexible fibre-shaped sensors developed by the group work in a very different way from conventional sensors. “Our technology works similar to a radar, but it sends out electrical impulses instead of electromagnetic waves,” explained doctoral assistant Andreas Leber. “The system measures the time between when a signal is sent out and when it’s received, and uses that to determine the exact location, type and intensity of deformation.”

The new fibre sensor has a number of advantages over conventional sensors which are fragile and break easily, which would be required in high numbers to cover a large area of fabric, and which are typically only able to detect one kind of deformation.

Creating the fibres used in the sensors was a complex task involving liquid metal, which serves as the conductor, and an optical fibre fabrication process. “The structure is just a few micrometres thick and has to be perfect, otherwise it won’t work,” said Leber. With these fibres, the entire surface of a fabric becomes one large sensor.

“The trick was to create transmission lines made entirely of flexible materials, using a simple method that can be scaled up easily,” added the project’s leader Professor Fabien Sorin.