One of the fundamental requirements in wearable electronics is to make it stretchable, flexible, elastic. Without this properties there is no way electronics can be integrated into clothing.
Over the past years various research and development activities have been undertaken to master the stretchability of electronic elements, to make electronic systems conformal with the textile properties used for clothing.
Many promising demonstrations have surfaced but up to this day there is no real ‘go-to’ solution when it comes to the integration of some electronic components into garments offering at least some percentage of stretchiness.
As many DIY wearable technologists know for a long time, using a zig-zag stitch is the best way to give some stretchiness for conductive lines between electronic components sewn onto textiles.
Using a sewing machine with zig-zag stitch is perfectly OK for prototyping. I have even used a computer controlled sewing machine doing the zig-zag connection for small scale production of a few hundred units successfully. My experience with this technique is: it becomes cumbersome on larger objects and production quantities going over 200-300 units. The robustness of this technique is not that great either, it requires the production of additional layers of fabric to sandwich the conductive yarn carrying fabric on both sides which provides to a certain degree wear and wash protection.
One of the more interesting stretchable electronics developments I came across is developed by the University of Gent in Belgium. Their Stretchable Microsystems design addresses the needs of wearable electronic to make it more conformable with fabrics natural properties. The Stretchable Microsystem design suggest to break the electronic system into functional islands which are connected by stretchable, metallic interconnects.
The electrical components are still not bendable and stretchable but breaking the electronic circuit board into small functional until = islands and connect them with stretchable interconnections would be one big step towards truly flexible, stretchable electronic.
I like the concept of “Islandization” but the stretchable interconnection between the islands should not require a Polymerization as suggested. Polymer sheets will certainly take away the feel and ultimately the look of being fabric like.
If the stretchable interconnect could be made from fabric material, maybe using a sewing machine with zig-zag stitch and sandwich the conductive yarn layer between protective stretch fabric could do the trick.
Electronic components like sensors, wireless chip and microprocessors getting smaller and smaller, splitting the functions into very tiny islands is something that can be done today. Wha’s missing is a elastic, electrically conductive link between those components.