As we explore new ways to create more effective wearable devices to monitor our health, smart garments are appealing because they are easy to integrate into our daily life. Most researchers look at the problem from a component perspective; how do you create flexible and durable conductors that can connect sensors and controllers so that data can flow freely through the fabric. But what if you looked at the problem a different way? What if the flexible fibers were both conductors and sensors at the same time?
That’s the concept behind new flexible fibers developed at Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland. The researchers have created plastic fibers that can incorporate electrode materials and nanocomposite polymers. The fabrication process is similar to how optical fiber is made; you heat up a batch of material and then draw it through a tiny hole to create a fine fiber. By using special plastics, the EPFL team has managed to create fibers that remain flexible. They can even be stretched to nearly five times their original length without damage, and then will return to their original size and shape. The tricky part is that the original mass of material can contain electrode material or even solid nanoparticles at different layers. When heated and stretched, the different components retain their original positions in a 3D arrangement, but much closer together within the fiber. The result is a conductor that can also be used as an extremely sensitive pressure sensor, or detect other important data. For example, you could have an input keyboard embedded in your shirt sleeve.
This same material also could be used as an artificial skin that can sense touch, for robotics or prosthetic limbs. According to the researchers, the fabrication process is easy to scale and can be incorporated in fabric production in manufacturing volumes. This discovery could hasten the appearance of smart clothing for a wide range of applications, including health and medical monitoring.
