Technology developers from the UK have designed a new wearable technology where the garment itself becomes an active motion sensor. Xelflex uses bend-sensitive fibre-optics that are stitched inside the clothing to provide intelligent feedback for athletes without encumbering them with bulky electronics.

The makers say that until now smart fabrics have had multiple electronic sensors, making them bulky and sensitive to moisture. Xelflex's fibre-optic thread is robust enough for use in sportswear, with a small, credit card-sized, electronics pack being the only other component.

Xelflex inventor Martin Brock said making a wearable technology that was comfortable was a key factor.

"Xelflex is a breakthrough sensing technology based on optical fibres; where the optical fibre is actually integrated into the garment. And really it behaves like any other thread in that garment, there's no compromise between having a sensor that gives you feedback on your motion or your performance; and having some clothing that is comfortable and wearable and elegant as part of the everyday activities," said Brock.

The technology built on the developers' extensive experience in industrial fibre-optic sensors and low-cost impulse radar. Brock explained that Xelflex measures the scattering of light in the optic fibres where bending the fibre results in increased scattering and reflection, which can then be measured.

"As I flex my joint there, it changes how much that optical fibre is bent. And as that bending changes the properties of the light in the optical fibre change so that more light is scattered back towards the source. And we pick up on that extra scattering and that allows us to measure how much that joint is bent," said Brock.

Algorithms turn the results from the sensors into feedback that is useful for the wearer; for example, correcting posture and movement, and coaching them on how to improve.

"At the most basic level what we're doing is measuring joint angles. That in itself is not useful, because you don't want to know you've bent your wrist through 37 degrees; you want some more useful feedback. So what we then do is process those raw joint motions into something that gives intelligent feedback, acting like a virtual coach to improve your technique, or just allowing you to record your body motions in a training session with a coach and then compare what you're doing a couple of weeks later to what you were taught to do, to see if you've lapsed into your old bad habits," said Brock, who sees correcting a tennis serve, golf swing or ski technique as immediate applications for the tech.

Cambridge Consultants' Duncan Smith said Xelflex improves on current 'smart garments' which he says are little more than clothing acting as a support for a conventional electronic sensor, with no synergy between the two and where the electronic component often detracts from the garment. He wants to bridge the gap between technologists and fashion designers.

"Xelflex represents a major step forward in wearable technology because it's truly wearable - the sensor is actually built in to the fabric so you're able to design clothes that have the sensor built into them. This means that fashions designers can design the clothes rather than technologists designing wearable technology that's just a wristband or something like that. And that's a big step forward."

The developers say the Xelflex technology is now at an advanced stage, and they are looking to work with fashion and design companies who are able to integrate their fibre-optics into truly desirable sports clothing.