Leading international trade fair for technical textiles and nonwovens
Hall:12, Booth D15
International exhibitors will be presenting the entire spectrum of technical textiles, functional apparel textiles and textile technologies at Techtextil in Frankfurt am Main from 21 to 24 June 2022.
By combining textiles and electronics, a specific set of requirements and restrictions arise. On the one hand, the textile properties have to be maintained as much as possible. On the other hand, the integrated electronics have to be protected against mechanical wear and other types of negative influences that occur during the use case of the e-textile product.
The quality and reliability testing methods at the IZM are tailored to the specifics of hybrid e-textile products. Thorough testing ensures that our developments fullfill the high expectations and requirements our customers need. We offer e-textile testing for mechanical strain including static and dynamic tensile testing, bending, abrasion, temperature and humidity cycling as well as wash testing under standardized and application specific conditions. A subsequent failure analysis, using state of the art analytic equipment like micro CT, x-ray microscopy, SEM, focused ion beam or micro section analysis reveals failure mechanisms and weak points in the design.
Many e-textile applications – like monitoring of vital signs, heating pads, logging of ergonomic data, lighting or innovative human-machine-interfaces – require textile integrated sensors and electronic components. This combination of electrical components and soft textile materials and the resulting requirements concerning comfort, washability, design, reliability or signal stability makes the integration a complex challenge. Interconnecting electronic modules is especially demanding. When it comes to dynamic mechanical stability, reliable contact resistance or sufficient washability, conventional e-textile contacting methods – snap fasteners, crimping, soldering, embroidering, conductive adhesive or sewing – often don’t lead to satisfying results. The e-textile bonding technology developed at the Fraunhofer IZM solves these issues by contacting electronic modules to textile circuits mechanically and electrically in one single step. The resulting bonded interconnections exhibit outstanding reliability under cyclic temperature and humidity strain, as well as excellent washability.
Using e-textile bonding, you can:
Compared to other established technologies, e-textile bonding:
Download: Flyer TextilBonder.pdf (2MB)
In the last years, the interest in stretchable electronic systems that can be 3-dimensionally bent and formed (conformable electronics) has risen considerably. For textile integrated electronic systems (e-textiles), the mechanical stress for the electrical components is especially high, due to constant dynamical strain during use as well as due to washing and cleaning procedures.
In addition to the existing technology portfolio at the IZM; there are now also textile circuit boards - based on silver coated textiles embedded in a thin thermoplastic elastomer matrix - available. Using lasercutting, the textiles can be structured into any geometry and design to create circuit paths or sensor areas. Integration into a textile substrate is done via lamination.
During the past two decades a number of product concepts electronic build-ups have been developed, which inherently demand a certain degree of stretch (elongation, extension) to be accommodated within the electronic systems.
Fraunhofer IZM developed a technology to fabricate “stretchable printed circuits”. The dielectric carrier material of these circuitries is thermoplastic polyurethane as opposed to the glas-fibre-epoxy compound of rigid or Polyimid (PI), Polyethylenterephtalat (PET) or Polyethylenenephtalat (PEN) for flexible circuits.
Conductor tracks on the stretchable circuits are similar to the conventional printed circuits made of copper. However, depending on the use case a more or less pronounced meandering design is used in the stretchable circuits, in order to allow for an extension of these tracks. Automated assembly of commercially available components onto these circuits is possible.
Electronic systems thus fabricated withstand repeated extension and release cycles until fatigue failures of the conductor tracks occur. Depending on the layout, up to 300 % extension is possible until the first tensile break.
Typical application areas of stretchable electronic systems are medical devices (electronic band-aid), textile electronics and electronic skin as part of future robotics.
The e-textiles prototyping toolkit is an intuitive and easy-to-use system, giving access to e-textiles not only to experts in electronics and programming but also to users from the creative sector, such as textile designers and fashion professionals. In addition to criteria addressed by other already existing E-textile kits (e.g. didactics, creative use of technology), the following three aspects are being considered in the system design through means of miniaturisation and different ways of contacting:
The e-textiles Toolkit offers multiple ways of electrical contacting and comprises a set of electronic modules. A main control unit (MCU) – connected with a selection of different sensor and/or actuator units – collects data and controls. Besides, this MCU provides a wireless data interface to communicate with handheld devices and a complementary app. The system automatically detects the other employed modules, and provides suitable user interface on the handheld device after connecting.
The textile prototyping lab (TPL) is the first open lab for high-tech textiles in Germany. Its multidisciplinary approach and the excellent prototyping capabilities make the TPL a perfect choice for complex and innovative textile and e-textile developments. With design and
technology experts from Fraunhofer IZM and weißensee academy of arts working together, the TPL guarantees high quality, holistic developments.
Fraunhofer Institute for Reliability and Microintegration IZM