A pair of EPFL researchers have developed groundbreaking technology that can be used with textiles to track a body’s movements. The holy grail of wearables! Professor Fabien Sorin and doctoral assistant Andreas Leber, at the Laboratory of Photonic Materials and Fibre Devices (FIMAP) in EPFL’s School of Engineering, have created a sensor that detects various fabric deformation, such as stretching, pressure, and torque all at the same time. These fabric deformations can give us more information about the human body.
“Imagine clothing or hospital bedsheets capable of monitoring your breathing and other vital movements, or AI-powered textiles that allow robots to interact more safely and intuitively with humans,” says Leber. “The soft transmission lines that we’ve developed open the door to all of this.”
Conventional sensors have limitations. They can only detect one kind of deformation, and they’re very fragile. To create the new sensor, Sorin and Leber incorporated concepts from reflectometry to create soft fiber-shaped sensors for smart textiles. The fiber sensors act more like transmission lines as they emit electrical pulses. The system then measures the time between when a signal was sent and when it’s received. This information is used to find the exact location, type, and intensity of deformation.
The fibers are created with an optical fiber fabrication process applied to unusual materials, like elastomers or liquid metals that act as conductors. The transmission lines are made entirely of soft materials via a simple process that can be scaled up. The fibers now enable the entire surface of a fabric to act as one large sensor.
This marks the first time detection technology has been used in structures combining extended mechanical flexibility and high electronic performance, key factors for measuring deformations. Next, the team will work on making the technology more portable by reducing the footprint of the peripheral electronics. With more time and development, they envision these smart textiles being used for various applications, like health care and robotics.