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46 PCB007 MAGAZINE I APRIL 2018 ductive fibers, conductive yarns, conductive coatings, conductive embroidery, and conduc- tive laminations. The electronic components can be sensors (physiological and environ- mental), wearable computing, wearable actu- ators and control elements, integrated circuits, LEDs, OLEDs, batteries, etc. The components can be passive (e.g., fiber optics) or active, and even interactive. What is the most exciting technology development since you started? One exciting technology that Connie de- scribed is interactive textiles where there may be a sensor or an electrical or thermal trigger for the fabric to assemble or disassemble it- self. One of the other applications that she has heard of but not yet seen is interactive camou- flage [1,2] . Fabdesigns has played with combining elec- tricity and thermal chromic inks. They have knit a jacquard into a fabric on industrial knit- ting machinery, painted it with black thermal chromic ink, and then used a heat source to re- veal the underlying jacquard on demand. We presented this fabric and self-disassembling fabric, using NiTinol at IFAI in September. Another is touch switches, using spacers. A spacer is a double-faced fabric, which is sepa- rated by Vs or Xs of another yarn that connects the two faces together. It forms a cushion in traditional fabric manufacturing, usually warp or circular knit roll goods. But in smart or e- textiles, a grid is knit into the fabric face and a different one on the reverse. Depressing the cushion in a particular area creates a circuit and can give location of that depression or act as a switch (capacitive sensor). If a sensor is added, the pressure rate of that depression can also be monitored. This can be used in Piezo electronic energy harvesting, security, and bio- medical applications such as bedding applica- tions in geriatric situations (bed sores), pediat- ric, and veterinary applications. What do you see as some of the challenges of merging electronics and textiles? Textiles and electronics are very deep fields. It's difficult to find people with both skill sets at the level needed to build projects. Almost all—98%—of textile equipment sold is for con- ventional apparel. Building technical textiles in and of itself is a specialized skill set, and men- tality. To build technical textiles, one must start from the polymer and build upward. There are few if any plug-and-play components (fibers, yarns, fabrics, coatings, etc. that are off the shelf) for building technical textile, let alone smart/e-textiles. Each project is different. The main issue is washability. Electronics do not take kindly to water. Battery size—depend- ing on what the product is supposed to do—is also an issue. The size required to do complex actions might be too large and cumbersome to wear. Another issue is recyclability. What do we do with these textiles once they are not work- ing, obsolete, or have reached their end of life? Can we repurpose them, recycle them or reuse them? At the moment, 85% of all our cloth - ing ends up in the landfill. It's an environmen- tal crisis [3] . Electronics has a similar track re- cord. There are electronics pick-up days and designated places to bring them, even waste disposal fees for getting rid of old and obso - lete products. In building smart textiles, we are blending two problems, unless we can de- vise exit strategies and build those into the de- sign process. Figure 1: Double-faced spacer fabric (shielding yarns).