Joint Project TexaS – Modular System for Smart Textiles

Fig. 1 (left): Final concept of the 2K interposer

Fig. 2 (right): Possible textile connection of the interposer: Stitching threads (green), contact threads (red)

Fig. 3: Technology demonstrator with embroidered and partially populated interposers (Source: TITV e. V., Greiz)

Technical textiles are used in a variety of applications due to their advantageous properties. These benefits arise from the high flexibility and variability of the materials used. Applications for technical textiles are found not only in clothing but also in many other areas, such as automotive interior.

An increase in the functional integration of textiles can be achieved by combining textile-electronic circuits with electronic components. Various technologies exist for connecting electronic components (sensors, actuators) to technical textiles, but they are still mostly inflexible solutions and do not allow for the exchange of different components. Such modularity is to be achieved through the research project.

Together towards innovative solutions

The overall goal of the collaborative project is to advance the development of textile-based and textile-integrated
microelectronic systems. The connection of peripheral elements and interchangeable components should be realized through cost-effective manufacturing technology. The focus is on developing reliable, efficient, and compatible contact and power supply solutions for variable functionalities.

The following collaboration partners have implemented the project:

- Textile Research Institute Thuringia-Vogtland e. V., Greiz (Coordinator)
- WESKO GmbH, Stollberg
- Robert Bosch GmbH, Renningen
- DFKI Interactive Textiles, Berlin
- Smart Battery Solutions GmbH, Kleinostheim
- ZSK Stickmaschinen GmbH, Krefeld
- Kunststoff-Zentrum in Leipzig gGmbH, Leipzig

Subproject KUZ: Development of process- and tool-technical solutions for injection molding of textile-based interposers and contact elements

The Kunststoff-Zentrum in Leipzig (KUZ) carries out the injection molding technical implementation of the respective sub-processes within the collaborative project. This includes the development and provision of switching carriers (interposers), which contact electronic components (sensors, actuators) on textile substrates via plug-in boards.

As the final interposer concept, a micro-formed part is developed, consisting of two different components (Fig. 1). The manufacturing of the corresponding molds is carried out with thermoplastic plastics on a micro-injection molding machine developed at KUZ, enabling the creation of interposers with complex geometries.

For the conductive contours and contacts, a metallizable component is processed together with an insulating material. After a metallization process, defined conductive tracks are formed. To fix the interposers, they are sewn onto the textile. The connection to the textile circuit is made by stitching conductive threads (Fig. 2).

Results

After simulation and optimization of the sub-components for the 2-component interposer, the design and manufacturing of the corresponding tools as well as the optimization of the tool components are carried out. Challenging aspects of the two-stage manufacturing of the interposers include demolding the miniaturized parts and the narrow process window.

On the functional interposers, a coating of copper, nickel, and gold is applied through partial metallization in a galvanization process. The project partners conducted functional tests with the final interposers and built a demonstrator (Fig. 3).

Contact person: Thomas Wagenknecht, Tel. 0341 4941603, wagenknecht@kuz-leipzig.de
Funding provider: BMBF, FKZ: 16ES0683