Interview with Ian Russell

The global market for smart garments and textile based wearables is expanding rapidly. Driven by a rising awareness within sectors, such as healthcare, sports and fitness, and the ability to monitor physiological information, such as heart rate and blood pressure. The smart garment/clothing wearables market is forecast to grow at a staggering 37.5 per cent in 2018-22.

Pireta is an e-textile start-up business that has been spun out of the National Physical Laboratory (NPL), a world-renowned scientific research establishment based in the UK. The original research work leading to our technology was performed by a team at NPL led by Chris Hunt, now Pireta's CTO and key founder. Chris's team was carrying out research into interconnect technologies for electronic systems and invented a novel chemical process in order to add conductive patterns to fabrics. Chris realised that this process overcame the many limitations of existing interconnect technologies for e-textiles. Recognising the commercial potential of the invention, NPL applied for patent protection and set up a new business to exploit the technology.

Pireta has received investment from a seed fund backed by the UK government, as well as private investment from two business angels with successful track records of supporting UK-based science and technology start-ups.

Pireta technology solves the recognised and critical industry challenge of providing robust interconnects for e-textiles that do not interfere with the performance of a fabric. By allowing electronic systems to be assembled and interconnected directly on fabrics, Pireta technology will enable a new generation of truly wearable smart garments and e-textiles. Garments produced with the process will be comfortable, washable, durable, stretchable and breathable. They will be truly wearable.

Pireta technology is a platform that enables the creation of wearable products based on e-textiles. Our 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.

No, there are other technologies available, but none of them offer the performance and manufacturability of Pireta. Until now, two technologies have been used for interconnecting electronic systems within e-textiles: conductive yarns and printed conductive inks. Although both technologies are functional, they have significant limitations when compared to Pireta technology. Conductive yarns can be woven, knitted or stitched into textiles to create circuits. However, knitting and stitching are not easily scaled for mass production and weaving does not allow free-form patterning. Also, conductive yarns have different properties to the native yarns in a fabric and adding them via stitching or embroidering is detrimental to the handle, drape and stretch of the fabric. Conductive inks are typically adhesive-type substances that have been loaded with silver particles. These compounds have a very limited ability to stretch without cracking. Textiles are generally not good substrates for adhesives; so, conductive inks are not typically applied directly to the fabric. Rather, they need to be applied on a plastic interposer or base layer. Again, this has a very detrimental effect on the feel of the fabric, and on the breathability and stretchability of any resulting garment.

There are a wide range of applications across multiple sectors-including healthcare, wellness & fitness, defence, emergency services and elite sports. The applications being developed by our partners typically involve collecting data on various physiological or environmental parameters, such as ECG, pressure, movement, strain, temperature, respiration rate, position, location, etc. Our initial marketing and business development efforts have been focused on Europe and the US. However, we recognise that consumer electronics, textiles, apparel and sports equipment, for example, are global industries. We are in discussions with lead customers in a diverse set of geographies. These include garment manufacturers in Europe and the Far East, as well as consumer electronics brands and healthcare/wellness players in the US.

The possible applications for Pireta technology will continue to grow over the years. We envisage growth across all the sectors mentioned earlier-and across a diverse range of applications. As pointed out, market analysts are forecasting that the market for clothing type wearables will grow at above 35 per cent CAGR over the next few years. We will continue to develop and enhance our technology and process. Our goal is for Pireta to become synonymous with e-textiles and intelligent garments.

The bond between the metallic layer and the fibres of the textile is very strong. The technology retains functionality over 100 wash cycles and is resistant to temperatures above <span lang="EN-GB" style="font-size:11.0pt;line-height: 107%;font-family:"Calibri",sans-serif;mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font: minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA">50˚C. There is no leeching 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.

Our process is compatible with several base metals. We are currently using copper as the metal that is plated onto the fibres to add conductivity. This is due to its excellent conductivity, wide availability and relatively low cost. The process can be carried out on a wide range of knitted, woven and nonwoven, natural, synthetic, glass and mineral-based yarns and textiles. The process results in a metal coating being plated onto the fibres of the textile. Because this coating is only a few microns thick, it adds negligible weight and has no impact on the handle, drape, breathability or stretchability of the textile. The process uses a free-form printing step to apply a catalytic seed layer that defines that shape and area that is subsequently plated. This means that almost any conductive pattern can be created. Conductive tracks can be widened in areas where there is space on the garment, but fine features can be used around electronic components and connectors. Track and gap widths of 1mm or less are typically achievable, depending on the fabric.

The wearables market is growing extremely rapidly year-on-year. In parallel, there is a transition under way from rigid boxed devices, such as smart watches and wrist bands, to smart garments based on e-textiles. The transition is being made possible by the availability of flexible electronic components and sensors that have been designed for wearability. However, the huge variety of textiles-along with their stretchable and conformal properties-means that they are a particularly challenging substrate in terms of interconnects. The absence of a robust, manufacturable and high-performance interconnect solution for e-textiles has been a major road-block for innovation in this area. This is where Pireta technology comes in. Removing this road-block will enable new product innovation and the explosive growth that is forecast for smart clothing type wearables.

We are expecting to license our technology to a number of high-volume manufacturing partners in the next five years. I also anticipate the Pireta process being used widely in the production of e-textiles and smart garments. Currently, we are working with prospective customers across a range of sectors and application areas-including fitness, wellness and elite sports. Some of the applications are very interesting and exciting.

The process is additive-meaning minimal waste -and uses readily-available, non-environmentally hazardous and low-cost materials. Pireta technology results in very small amounts of metal being added to the textile. Metals are not, by their nature, inherently biodegradable. However, as is the case with other electronic devices, it will be possible to recover and re-cycle these metals from smart garments produced using the Pireta process.