Tiny flexible sensors pave the way for smart clothes

A sensor based on silver nanowires is mounted onto a thumb joint to monitor the skin strain...

A sensor based on silver nanowires is mounted onto a thumb joint to monitor the skin strain associated with thumb flexing. (Shanshan Yao)

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, Last Updated: 12:00 PM ET

Scientists have found a way of making sensors small and flexible enough that they could be woven into fabrics.

The breakthrough could lead to everything from socks that refuse to get lost and red t-shirts that alert you when they find themselves loaded into the washing machine along with white shirts; to running shoes that count every step taken and three-piece suits that monitor the wearer's posture.

The sensors in question use silver nanowires, which are very elastic and make good electrical conductors, and were developed by researchers at North Carolina State University.

"The technology is based on either physical deformation or 'fringing' electric field changes. The latter is very similar to the mechanism used in smartphone touch screens, but the sensors we've developed are stretchable and can be mounted on a variety of curvilinear surfaces such as human skin," says Shanshan Yao, a Ph.D. student at NC State and lead author of a paper on the work.

The sensors are multifunctional - they can measure strain, pressure, human touch and bioelectronic signals such as electrocardiograms - and therefore have hundreds of potential applications beyond smart clothing.

"These sensors could be used to help develop prosthetics that respond to a user's movement and provide feedback when in use," says Dr. Yong Zhu, an associate professor of mechanical and aerospace engineering at NC State and senior author of the paper. "They could also be used to create robotics that can 'feel' their environment, or the sensors could be incorporated into clothing to track motion or monitor an individual's physical health."

As such the team has already demonstrated how the sensors can be used to monitor thumb movement as a means of controlling a robotic or prosthetic device and have used them to record a person's knee movements while running, walking and jumping.

"Creating these sensors is simple and low cost," Yao says. "And we've already demonstrated the sensors in several prototype applications."

The team's paper, "Wearable Multifunctional Sensors Using Printed Stretchable Conductors Made of Silver Nanowires," is published online in the journal Nanoscale.


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