After an international team, led by the University of Cambridge, demonstrated the feasibility of large woven displays that could be made using specialized manual laboratory equipment, it showed that other smart textiles can be manufactured in specialized microelectronic fabrication facilities.
The production using the Cambridge model however is highly expensive and produces large volumes of waste. Now the research team has reported in the journal Science Advances that flexible displays and smart fabrics can be made much more cheaply, and more sustainably, by weaving electronic, optoelectronic, sensing, and energy fiber components on the industrial looms used to make conventional textiles.
“We could make these textiles in specialized microelectronics facilities, but they require billions of pounds of investment,” said Dr. Sanghyo Lee from the Cambridge Department of Engineering. “In addition, manufacturing smart textiles in this way is highly limited, since everything has to be made on the same rigid wafers used to make integrated circuits, so the maximum size we can get is about 30 centimeters in diameter.”
Last year, some researchers demonstrated that if the fibers used in smart textiles were coated with materials that can withstand stretching, they could be compatible with conventional weaving processes. Using this technique, they produced a 46-inch woven demonstrator display.
Now they have shown that smart textiles can be made using automated processes, with no limits on their size or shape. Multiple types of fiber devices, including energy storage devices, light-emitting diodes, and transistors have been fabricated, encapsulated, and mixed with conventional fibers, either synthetic or natural, to build smart textiles by automated weaving. The fiber devices were interconnected by an automated laser welding method with electrically conductive adhesive.
The processes were all optimized to minimize damage to the electronic components, which in turn made the smart textiles durable enough to withstand the stretching of an industrial weaving machine. The encapsulation method was developed to consider the functionality of the fiber devices, and the mechanical force and thermal energy were investigated systematically to achieve automated weaving and laser-based interconnection, respectively.
The research team, working in partnership with textile manufacturers, was able to produce test patches of smart textiles of roughly 50×50 centimeters, although this can be scaled up to larger dimensions and produced in large volumes.
These companies have well-established manufacturing lines with high throughput fiber extruders and large weaving machines that can weave a meter square of textiles automatically. Further optimization of the process is however needed.
Smart textiles made commercially viable
