An expert’s perspective: e-textiles and connector technology
Audrey Le Houedec
Tech Lead at Genius Objects
The interface between textile and electronics: a challenge for connected textiles
In the field of connected textiles, a major challenge is the interface between electronics and textiles, particularly during the manufacturing phase of a product. On the minds of key industry stakeholders today is the question of how to approach the confluence of the textile industry on the one hand – soft; flexible; capable of withstanding pressure and constraints and the unyielding, rigid environment of circuit boards on the other, with their sensitivity to vibrations and deformations. How to ensure a robust and reliable connection between textile and electronic parts? How to sufficiently live up to the duties fulfilled by traditional textile products (washable, waterproof etc.)? Which technologies are appropriate for taking on these challenges?
Despite these questions being raised by all key industry stakeholders, as yet no one, standard solution has emerged. The latest projects covered in the media, such as Jacquard by Google, in collaboration with Levi’s, propose “plug & connect” systems. These make it possible to easily detach the electronic part from the textile part of the product. Nevertheless, solutions like these still leave it up to the end user to remember to remove, charge and re-connect their accessories in order for the item of clothing to remain a connected one. What is more, until now these solutions have been developed in-house, with production costs that only the “giants” such as Google are able to absorb.
Several solutions for connected e-textiles
Our research along with the experiments covered by the media suggest several other possibilities:
- Soldering: this is suitable only for connected wires or fabrics that can withstand high temperatures (about 300 degrees).
- Snap fastenings: these can be effective during the prototyping phase, but are difficult to carry across into the manufacturing phase.
- Rivets: these are useful for crossing conductive surfaces.
For Zip and Go®, our sensor that can be incorporated into a zipper, we studied many possibilities before finally arriving at a solution that can be fully integrated into textiles.
We opted for rivets, with a PCB plate to link them with the tape. The PCB enables us to ensure a robust connection that can adapt fully to the shape and form of our sensor, at a controlled cost. In addition, the minimal density means that the device is virtually undetectable, once it has been incorporated into the final product. The rigidity of conventional PCB can be a limitation for some projects: in such cases it can be replaced by flexible PCB, at a not insignificant additional cost.
This technology-driven approach has enabled us to industrialise Zip and Go® technology. We are bringing to the market a product that is reliable, functional and can be easily integrated into an already existing device, all at a controlled cost.
For further information, we highly recommend Florence Bost’s book on innovations in the textile industry, “Textiles: Innovations et Matières Actives”.