Computerised fabric that could one day transform any piece of clothing into a Fitbit-like fitness tracker has been developed.
The fabric is made using soft and stretchy sensors that can transmit data on a wide range of human body movements.
The highly sensitive technology could be used to create 'smart apparel' in which your clothes double up as digital devices.
Most of the sensors used to collect and transmit data in today's wearables are made of hard materials that are uncomfortable and can restrict the wearer's movements.
But the team of scientists, from Harvard University, Massachusetts, has now incorporated computing elements into the fabric itself to create a wearable sensor that comfortably flexes with the human body.
As well as fitness tracking sportswear, the fabric could one day help with movement in long-term healthcare by forming a soft exoskeleton around users.
'We're really excited about this sensor because, by leveraging textiles in its construction, it is inherently suitable for integration with fabric to make "smart" robotic apparel,' said study coauthor Dr Conor Walsh.
Lead author Professor Donald Ingber added: 'This technology opens up entirely new approaches to wearable diagnostics and coupled therapeutics that undoubtedly will pay a central role in the future of home healthcare.'
The team's technology consists of a thin sheet of silicone sandwiched between two layers of conductive fabric, creating what's known as a capacitive sensor.
This kind of sensor can track even the slightest movement by constantly monitoring tiny electrical charges as they travel through the material.
'When we apply strain by pulling on the sensor from the ends, the silicone layer gets thinner and the conductive fabric layers get closer together, which changes the capacitance of the sensor in a way that's proportional to the amount of strain applied,' said co-author Dr Daniel Vogt.
'We can measure how much the sensor is changing shape.'
The material is sensitive enough to measure physical strain from movements of less than half a millimetre, the researchers said.
To test this, the researchers integrated a set of the fabric sensors into a glove to measure small hand and finger movements in real time.
The sensors successfully detected capacitance changes on individual fingers as they moved, tracking their relative positions over time.
'Our sensor's greater sensitivity means it has the ability to distinguish smaller movements, like slightly moving one finger side-to-side rather than simply whether the whole hand is open or clenched in a fist,' said co-author Ms Vanessa Sanchez.
The material is only a preliminary proof of concept for now, but the researchers hope that the flexible technology could be used for motion capture applications.
These applications include sports attire that tracks performance or soft clinical devices to monitor patients in a medical setting.
'This work shows promising results for human motion monitoring in sports, for performance optimisation, or training purposes,' coauthor Dr Ozgur Atalay told Seeker.
'For example, a golfer who wears sensor integrated clothing can train himself on correct posture, or an athlete can optimise his performance by learning from sensor feedback.'