Electronics in textiles may be printed or wound using wires and there are other options, with over 100 organisations working in the field. It varies from the invisible to the fanciful.
Fabric electronics is primarily used for sensing as in health monitoring, warming as in outdoor wear, display and lighting including illuminating t-shirts and party fashions and control as with sleeve controls for your i-Pod and woven rollable keyboards shown below.
Then there is logistics, notably RFID. That includes active RFID where there is a battery in the tag for real time location, mesh networking and so on. These batteries will have energy harvesting in future.
Adidas pulls ahead
As reported by Stacy Burr speaking at the IDTechEx Energy Harvesting event in Denver in November 2009, Adidas is taking it further forward with such concepts as the virtual trainer.
Stacy reported that there are more e-textile products than ever in the market and the increased volumes are helping drive cost down. There is less talk of technical challenges and the sector is attracting investment with major brands and retailers participating.
Adidas acquired Textronics, a spin out from DuPont/ Envista in 2008. It focuses exclusively on textile electronics, specifically Wearable Physiological Monitoring Systems. Here the vision is to easily measure body data to help consumer manage health and wellness goals. Consumer distribution has been employed - first as NuMetrex, now through the Adidas brand. These products are part of the miCoach heart rate coaching concept. It also markets B2B Professional monitoring textile sensors through partners. The Adidas approach is very broad from military to care for the elderly and sports.
As Adidas points out, textiles are the most common human interface because 70% of surfaces touched each day are textiles, including clothes, bedding, wall covering, upholstery and flooring. Textiles areflexible, comfortable and consumer oriented. They are stretchable & conformable and they present large surface areas to work with. They are highly engineered and ordered structures produced by an established, efficient, global supply chain and a mass volume application platform.
Currently, the main materials employed in textile electronics are conductive inks, metal wires, plated synthetic fibers and filaments, plated, etched fabrics and conductive polymers. Textro conductive stretchable yarn by Textronics is shown below.
Complete circuits are being incorporated into textiles such as the one below.
Source Sauquoit Industries
Challenges and opportunities
Adidas sees some of the challenges and opportunities as:
- Low Power electronics : Micro to milli watts for wearable monitoring systems; Several watts for heating system
- Sustainable power - enviro friendly
- "Lifetime" power - 6-18 months, 100 washes/wears
- Trend towards body distributed networks - don't want multiple battery cells
- Energy Harvesting Options : Thermo-Electric harvest - body/environmental differences; Motion - foot, elbow, knee, hip or general twist; Intelligent storage & power management
Top image source Maker Faire
For more read : Energy Harvesting and Storage for Electronic Devices 2009-2019