Washable E-textiles: Challenges and New Standards

With the help of E-textiles, you can start to wear tech with smart functions directly on your body. But just like normal clothing, they need to be washable. Sigrid Rotzler is investigating how wearable E-textiles can be optimized for the washing process. She was involved in the development of one of the world’s first standards for the reliability of E-textiles: IPC-8981, Quality and Reliability of E-Textile Wearables.

E-textiles, i.e. textiles with embedded electronic components, offer a promising solution for jobs in areas ranging from sports to medical technology or occupational safety. Smart items of clothing can track training progress, collect patient data or warn their wearers if they detect specific hazards. At the same time, they are often exposed to certain forces that are challenging the durability and comfort of even traditional textiles. When you then add sensors, circuit boards, or conductor tracks to the piece of garment, it turns something that would normally be simple – washing it – into a problem. This is why the IPC-8981 standard on the ‘Quality and Reliability of E-Textile Wearables’ was created as one of the first standards governing the reliability and washability of E-textiles.

IPC-8981, Quality and Reliability of E-Textile Wearables specifies criteria and test methods that can be used to assess the reliability and durability of E-textiles exposed to various mechanical stresses such as abrasion, bending, or UV exposure – and environmental conditions such as perspiration, washing, water/salt water, alkalis, or acids.

Another important standard is DIN EN ISO 6330, Textiles – Non-commercial washing and drying methods for testing textiles. It helps assess the washability of textiles and provides a basis for washing tests with E-textiles.

»The big challenge with E-textiles is that they are fitted with electronic components that are not particularly well-suited to being put in a washing machine. They are not as soft, they are not as flexible, they can oxidize, they can break. Nevertheless, they have to go in the washing machine«, Sigrid Rotzler, research assistant in the »System on Flex« research group, knows. What’s more, the damage patterns after washing are not uniform: »It may happen that a conductive coating gets detached. Very thin wires that are in the textile conductors can break. Some conductors are particularly susceptible to buckling stresses. Some are more susceptible to tensile loads or temperature changes.«

Typical damage to E-textiles after repeated washes. Mechanical stress in the washing machine is particularly hard on the conductor tracks. | © Fraunhofer IZM

Not only the electronic components, but also the properties of the textile substrates are important for the washability of the system structure. Cotton, for example, soaks up water, whereas synthetic fibers tend to be more water-repellent. Knit fabrics give you more design freedom, but they are soft and not very durable. All of this also has an influence on the embedded electronic components.

The »System-on-Flex« group at Fraunhofer IZM has been researching innovative E-textiles for over 20 years. The laboratories are equipped with a whole battery of production and testing machines just for this purpose. This enables engineers and designers to work together to develop prototypes that are reliable not only when worn, but also when washed.

As part of the Expert Session Series »Electronic Solutions for Challenging Environments«, Sigrid Rotzler presented a series of tests she conducted on the washability of E-textiles. In her presentation, she provided valuable insights into the question of how and where textile-integrated circuits need to be optimized in order to improve their washability. One focus of this was the interactions between the textiles, the electronic components and the entire assembly.

Recording of the online expert session »Towards washable eTextiles: Factors influencing the wash safety of textile-integrated electronics« from March 18, 2025 © Fraunhofer IZM

The development of E-textiles is a very dynamic field in which new requirements for technology and materials are constantly being formulated. So far, it has only been possible to fall back on a few standards. It is generally agreed that the mechanical stress to which E-textiles are exposed in the washing process causes the most damage. However, high temperatures, bleaching agents, and long washing times are also critical factors.

The Sinner’s Circle: cleaning success in the interplay of mechanics, duration, temperature and chemistry | © Fraunhofer IZM

A classic model for the factors that influence the washing process is the Sinner’s Circle: the effectiveness of cleaning depends on the interaction of mechanical movement, duration, temperature, and chemistry. When optimizing the washability of E-textiles, the effect of these factors on the electronic components must be considered.

»With this in mind, we developed a washing test protocol based on ISO standard 6330, a textile washing standard. We used it to wash various textile substrates and different circuits,« Sigrid Rotzler says about the procedure. »We then test parameters that characterize the washability. This can be, for example, a change in the resistance in a component or a loss of functionality. This test protocol can be adapted again if the reliability requirements are particularly high.« The results clearly show that the response of E-textiles to being washed depends on many factors and interactions.

Damage patterns of E-textiles after washing tests: From left to right: Madeira (embroidered conductors) – loss of conductive coating after washing tests (without overstitching after 20 cycles); Elektrisola (hybrid conductors) – X-ray after 100 washing cycles | © Fraunhofer IZM

Damage patterns of E-textiles after washing tests: From left to right: TexPCB (textile printed circuit boards) – loss of Ag coating after washing tests; Nanoleq (elastic hybrid conductor) – results after washing tests: X-ray | © Fraunhofer IZM

Sigrid Rotzler cannot give any general washing recommendations for E-textiles. She refers to a »knowledge matrix« that can be used for the development of E-textiles. It must first be clear which requirements the garment has to meet: »Will it be customized or is it one-size-fits-all? Which sensors are installed, and where are the conductor tracks? Does it need to be washed frequently and at high temperatures, or less frequently and more gently? In this case, I would opt for this type of conductor or that type of processing method. Then I might have to reinforce an area or install some protective mechanism.« Sigrid Rotzler’s research and her involvement in the development of the new IPC-8981 standard represent an important contribution to the further development of this knowledge matrix.

Save the dates:

Reliability will also be a topic at the E-Textiles Conference 2025, which will take place from November 12 to 14, 2025 in Roubaix, France. Sigrid Rotzler will speak at the conference. On June 11 and 12, the Future of Electronics RESHAPED conference will take place in Boston with a presentation by group leader Malte von Krshiwoblozki.