French researchers, based at the Ecole Polytechnique Fédérale de Lausanne, have discovered a rapid and relatively simple means to create make super-elastic, multi-material, high-performance fibers. These fibers have begun to be used as sensors to increase the responsiveness of robotic fingers. The next step is to use the fibers for the development of smart clothing. In addition the smart textile concept could also be applied to medical implants.
What is important about the fibers is the base material, which is an elastomer. This material can incorporate other materials, such as electrodes and nanocomposite polymers, which offer new functionality. Furthermore, the fibers are able to detect very slight pressure differentials and strain, offering advantages as sensors.
While the inclusion of electrodes provides a key factor in the development of smart clothing (for communication or power generation), the flexibility of the fibers is also of great importance. The fibers, in tests, have been shown to be capable of withstanding deformation at a level close to 500 percent. Following such distortion, the fibers can quickly recover their initial shape. This makes the fibers ideal for applications in smart clothing and prostheses.
To fabricate the fibers, the researchers used thermal drawing. This began with a macroscopic preform with the various fiber components arranged in a pre-designed three-dimensional pattern. Following this, the scientists heated the preform and stretched it out in order to reduce the fibers to a few hundreds microns in diameter. At the same time as stretching out the pattern of components lengthwise, the process simultaneously contracted the fibers crosswise. This meant the the components’ relative positions remained the same, resulting in fibers with complicated microarchitecture and the potential for advanced properties.
The following video explains more:
The research has been published in the journal Advanced Materials, with the peer-reviewed paper published as “Superelastic Multimaterial Electronic and Photonic Fibers and Devices via Thermal Drawing.”
