The wearables market is quickly transforming from rigid boxed devices, such as smart watches and wrist bands, to smart garments based on e-textiles. Taking this transition one step further is Pireta, a UK-based company whose technology enables “truly wearable” smart garments and e-textiles. Made possible by developing a unique and patented free-form printed circuit process that allows electronic systems to be assembled directly onto textiles, Pireta’s technology makes the fabric itself conductive. Here are five things you need to know about Pireta’s technology.
 
1. How does the technology work?
 
Pireta’s technology uses an innovative chemical process to make areas of fabric electrically conductive. The process, which incorporates a printed step, is free form and selective – almost any conductive pattern can be printed directly onto an existing textile. The technology allows electronic systems to be assembled directly on fabrics, enabling a new generation of truly wearable smart garments and e-textiles.
 
The conductivity is provided by a very thin metallic coating that is chemically bonded to the fibers in the fabric. Typically, fabrics are knitted or woven from yarns or threads that have been created by spinning together a bundle of fibers. Pireta’s process is applied at the fiber level, coating the individual fibs with a layer of copper that is only a few microns thick. As a result, the fibers retain their ability to deform and move, avoiding any impact on the handle, drape, breathability or stretch-ability of the fabric. The process adds negligible weight to the textile and allows conductivity to be added discretely, only where needed.
 
Pireta’s technology is a platform that enables the creation of wearable products based on e-textiles and smart garments. The technology not only provides an ideal component interconnect solution for e-textiles, but it can also be used to create a range of sensors and transducers. It is also compatible with RF signals, allowing the integration of wireless technologies, such as NFC, RFID, Bluetooth and Wi-Fi into e-textiles and smart garments.
 
2. What makes the technology different?
 
In the past, there have been two main technologies used for interconnecting electronic systems within e-textiles: conductive yarns and printed conductive inks. Pireta technology has several key advantages relative to these approaches and these advantages are critical to the successful development and production of smart garments. For example, neither conductive yarns or printed conductive inks being suitable for direct soldered connections, a method used almost universally in the electronics industry. Pireta’s technology is applied directly to the original fabric and has no impact on the original handle, drape, stretch-ability or breath-ability of the fabric, unlike conductive inks, which require a plastic interposer or base layer to be bonded to the textile.
 
Pireta technology also allows free form patterning and is easily scaled for high-volume production. Compare this to conductive yarns, which need to be stitched or embroidered into fabrics to create interconnects, making the technology difficult to scale. Conductive yarns can be woven, but this approach cannot create free form patterns or be applied to existing textiles. In addition, conductive yarns have different properties to the native yarn in the fabric and their introduction – therefore stitching or embroidering will also be detrimental to the performance of the fabric.
 
3. Will conductivity be lost when putting smart garments in wash?
 
No. The bond between the metallic layer and the fibers of the textile is very strong. Wash tests have been carried out on samples and they showed that the technology retains functionality over 100 wash cycles and is resistant to temperatures above 50˚C. There is no leaching of the metals that form the conductive tracks during washing and the conductivity is retained with stretching. The tracks are resistant to abrasion and bending. Furthermore, organic coatings can be used to provide additional protection against moisture, sweat and other substances.
 
4. How are connections made to Pireta conductive tracks?
 
Electronic components and connectors can be soldered directly to tracks and fine-geometry pads created with the Pireta process, provided the host textile has sufficient temperature resistance. Depending on the fabric, low-temperature solders may be required. Pireta conductive patterns are metallic, and therefore there is no limit on solder temperature imposed by the Pireta conductive tracks. Pireta’s technology is also compatible with other connection technologies and systems, including crimping/compression type connectors for e-textiles, conductive adhesives and conductive threads.
 
5. Can the technology be used for mass production?
 
Yes. The technology uses a “factory in a box” approach, allowing the Pireta process to be licensed to end-to-end garment manufacturers, as well as to contract manufacturing partners wanting to offer a printed conductive textile process as a service.
 
The Pireta process uses direct soldering, a method used almost-universally by the electronics industry for mounting and connecting components to circuits, making it highly scalable. It can also be operated roll-to-roll at a mill or applied later in the garment manufacturing process to either cut or finished garments.
 
Dyes and protective treatments can also be applied to the textiles that have been functionalized using the Pireta process. The process uses commercially available equipment and is additive – meaning minimal waste – and uses low-cost materials that are readily available and not environmentally hazardous. It is also suitable for integration within the textile and garment manufacturing industry, as well as being compatible with existing electronic manufacturing.
 
Ian Russell is chief commercial officer, at Pireta. He has more than 20 years of experience managing early-stage business ventures working in high-technology sectors. Russell has built and managed international development, sales and service organizations and negotiated multi-million dollar technology licensing contracts and strategic alliances with key vendors and partners. He led three successful trade sales of early-stage technology-based businesses to publicly listed companies.