Covestro films light the way for smart electronics

Covestro has created a luminous dress to showcase how its latest materials developments can be used with LEDs to produce smart and functional clothing for a number of end uses, such as pedestrian safety or health monitoring.

The dress is lit up by light-emitting diodes (LEDs), but uniquely these are not positioned on a panel or strip, but on a piece of soft fabric. At the centre of the development is an electronic system that is responsive to movements without losing its functionality.

The system that lights up the dress comprises a flexible and formable film made of thermoplastic polyurethane (TPU). The TPU is the substrate for the printed copper circuits, which are arranged in a meandering pattern and can, therefore, also be bent and stretched.

To manufacture the smart circuits, copper films are first laminated onto the polyurethane films. The printed circuits are produced in a subsequent structuring operation featuring highly effective adhesion. The coated films are then shaped as required using conventional thermoforming.

“The films are resistant to standard etching and imaging processes,” said Covestro Film Expert, Wolfgang Stenbeck. “Formable electronic systems can also be directly laminated onto textiles, as in the case of the luminous dress.”

The smart circuits meet a whole range of customer needs and are therefore ideal for applications in a variety of industries. Compared to conventional electronic components, they offer greater design freedom and reliability while enabling more sustainable products due to the reduced use of materials.

For example, the technology opens up an extremely wide range of options for smart textiles alone. Besides fashion items, such as the luminous dress, freely formable electronic systems are already in use in underwear, where they monitor heart rate and breathing. They assist patients with therapy and help athletes monitor their training.

The production technology was developed as part of various projects funded by the EU Commission, including ‘STELLA’ and ‘TERASEL’. The dress will be on display on Covestro’s stand at K 2016 next month.