With the emergence of wearable electronic devices that can detect movement and health conditions, there is a growing demand for more flexible light-emitting devices. One area of interest to researchers is the development of fabrics with integrated light-emitting devices. Unfortunately, cloth itself does not serve as a suitable surface for luminescent materials. However, a team of scientists has found a solution to this problem by integrating light-emitting devices directly into fabrics using a new technology called light-emitting device fibers.
This research team from my country has developed polymer light-emitting electrochemical cells (PLECs). Like many other light-emitting devices, PLECs have two metal electrodes connected to a thin organic layer that acts as a semiconductor. Because PLECs incorporate mobile ions into semiconductors, they have many advantages over other light-emitting diodes (LEDs): low operating voltage, high photoelectric conversion efficiency, and high power efficiency. PLECs are a good choice also because they do not require the use of air-sensitive metals and can be used on rough surfaces. These characteristics make it suitable for mass production.
These fibrous PLECs have a four-layer coaxial structure. PLEC fibers are prepared using a solution method. First, steel wire is used as the matrix of the fiber, and then a thin layer of ZnO nanoparticles is dip-coated. This layer has two main functions: protecting the following light-emitting layer, while reducing leakage current and improving current efficiency.
Next, an electroluminescent polymer layer is deposited on the surface of the steel wire using a dipping method. Finally, a neatly arranged layer of carbon nanotubes is wrapped in the outer layer of the steel wire bundle. The carbon nanotubes use dry-drawn spinnable carbon nanotubes. Because the carbon nanotube structure is highly uniform, they provide the fiber with high electrical conductivity. The photos show that the fiber diameter is uniform and the outer surface is smooth.
The scientists who created the fibers studied the longevity of the devices. They found that the fibers gradually lit up over 21 minutes and dimmed over four hours; in this study, the light emitted by the fibers was blue. When a voltage of 5.6 V was applied, the fiber was lit; when a voltage of 13 V was applied, the fiber current intensity reached its peak value. When the fiber was precharged, it showed a fast turn-on response similar to traditional LEDs.
The brightness of the light emitted by the fiber is almost completely unaffected by the viewing angle. Even if the fiber is bent, it can maintain brightness above 90% without obvious damage. While only blue was studied in this exploration, the team believes other colors have similar effects.
Based on these studies, these luminescent fibers can be woven into fabrics without damaging their luminescent properties. This makes them strong candidates for the future development of wearable electronics and other woven electronics.
Extended reading: https://www.yingjietex.com/product/Ottoman -Pongee-coated-breathable-Fabric.html
Extended reading: https://www.alltextile.cn/product/product -51-811.html
Extended reading: https://www.brandfabric .net/ottoman-pongee-coated-breathable-fabric/
Extended reading:https ://www.alltextile.cn/product/product-9-239.html
Extended reading: https://www.tpu-ptfe.com/post/3321.htm
