At the IDTechEx, Fraunhofer ISC will show a new class of mechanical sensors suitable for integration into woven or knitted fabrics for use in medical devices, as well as a novel kind of pressure stocking developed together with Fraunhofer IIS.

Apart from the textile-integrated sensors, Fraunhofer ISC will also present its expertise in printed electronics, 3D printing, thin film batteries, and multifunctional barrier coatings for flexible films.

Elastic sensors integrated in textiles

A new class of mechanical sensors is especially suitable for integration into woven or knitted fabrics because of their high elasticity and their soft and flexible characteristics, the organisation reports.

These dielectric elastomer sensors (DES) can be integrated into the textile by bonding or sewing, and can be used to measure deformations, forces and pressures. Very high strains up to 100% and more can be achieved, according to the manufacturer.

DES consists of a very elastic elastomer film coated with highly flexible electrodes on both sides. By patterning the electrodes on the elastomer film an array of many elements can be built up. The textile-integrated sensors are washable and are said to show a high wearing comfort

Applications for medical and training

The textile-integrated elastomer sensors are applicable in medical devices, such as for preventing bedsores or for localizing the pressure distribution in shoes. They can also support personal training by measuring the posture via the clothes or as an input device for game and fitness device controlling.

The textile form is very variable – if it’s a stocking, glove or shirt – as the sensors are designed to be stretchable and easy to process. Beyond that DES are said to improve industrial safety, for example, of human-machine interfaces in collision detection systems.

3D pressure readings for diabetics

At the IDTechEx, Fraunhofer ISC will show a novel kind of pressure stocking developed together with Fraunhofer IIS. It is designed to protect diabetics against wounding via an integrated sensor system that sends a warning signal when pressure in the shoe is locally too high. Fraunhofer ISC has submitted this project for an IDTechEx Award 2015.

In total, 40 very fine, dielectric elastomer sensors measure compression load and distribution in the stocking. They are attached to the stocking’s sole, the heel, the top and the ankle, in order to achieve a three-dimensional reading. If a patient stands in one spot for an extended period, pressure will rise. The sensors recognize this rise and transmit the measurement signal via a conductive thread to a low cost wireless electronic unit.

The application-specific integrated circuit (ASIC) chip collects the measurement data from 40 capacitive sensors and the controller transmits the data wirelessly to a smartphone or tablet e.g. to advise the diabetes patient to change foot position or weight distribution.

www.isc.fraunhofer.de