3D stretchable strip to transform wearable e-textiles

This advancement was spearheaded by a team at Nottingham Trent University’s Medical Technologies Innovation Facility, setting the stage for a new era of electronic devices that can be seamlessly integrated into clothing, potentially benefiting healthcare and elite sports applications.

The team claimed that the new strip offers substantial advantages and enhanced functionality over existing technologies due to its capacity to stretch and conform to the body's movements.

Featuring a 3D structure where the circuitry is twisted into a helical ribbon, the strip transitions from being merely flexible to fully stretchable. It can bend in multiple directions, not just one, and can stretch to at least half of its original length.

Stretchability is a crucial attribute, especially for textiles like medical compression garments or sportswear, which must allow for unrestricted movement.

“We have been able to show the potential for a new form of 3D helical strip for embedded electronics in e-textiles,” said Dr Yang Wei, an expert in electronic textiles and electronic engineering at Nottingham Trent University and the principal investigator of the research.

He said: “We have defined the design, developed prototypes, performed mechanical testing and validated the functionality of the concept. This opens up a range of new possibilities for e-textiles for possible future use in healthcare and elite sports settings.”

Lead author Jessica Stanley, a research fellow in the university’s Medical Technologies Innovation Facility and Department of Engineering, said: “The basic idea has been around for centuries; it's the same concept as taking a metal wire and making it stretchy by winding it into a spring. While helices have already been used in stretchable electronic devices, up to now they have only been used as interconnects – wires that connect parts of a circuit – or single components.

“What sets our work apart is that strips of flexible circuitry containing small components, circuits more complex than a single wire or printed component, are wound into a helix, so that the entire circuit can stretch.

“Because many e-textile products need to be stretchy it is important to have stretchable electronic parts that can move and stretch with the fabric. This study documents our initial work on a new way to achieve this.”

As part of the research, the team showcased LED and temperature-sensing helical e-strips. A rubber cord reinforces the structure, preventing damage from buckling, and ensuring compatibility with clothing and washability was also considered.

The technology has been patented, which it is hoped will facilitate quicker adoption by industry.