Recently, the MIT team of the United States directly woven light-emitting diodes (LEDs) and sensors into textile-grade polymer fibers through a new manufacturing method. The process can be used to develop new wearable technologies that enable optical communication and health monitoring.
Semiconductor diodes capable of emitting or detecting light are essential components of communication and sensor technology. If they can be incorporated into fabrics, it is expected to create new wearable electronic devices. However, combining the functionality of semiconductor devices with the scalability of fiber-based textiles is a tricky business.
The researchers started with a larger polymer preform and embedded the semiconductor device into the hollow channel of the preform. Then, the preform is heated and stretched while threading the wire into the hollow passage to form an expanded fiber bundle. In this way, the electrically connected light emitting or photodetecting diodes are evenly distributed axially within the fiber bundle.
The process is inherently scalable and can produce functional fibers hundreds of meters long. Once stretched, the fibers can be easily woven into the fabric. The research team put these diode fibers into a standard household washing machine for ten laps and found that their performance was not damaged, proving their durability.
Researchers say that a two-way optical communication link can be established between two textiles containing light-detecting and luminescent fibers, which can also be used to measure the wearer's heart rate. This new manufacturing process enables people to create textiles with more advanced features, and smart textiles and wearable technologies will become increasingly sophisticated in accordance with their own "Moore's Law."
The research results have been published in the British journal Nature.