E-textiles: Pipe Dream or Future Reality?

Embedding electronics in our clothing, shoes, or accessories is not a new concept. The next big leap in this area, however, could result in designers embedding sensors into the actual fibers of a fabric – a core concept that is driving the e-textile industry.

Two examples of e-textile research: a knitted heated glove (left) and a light-emitting e-yarn (right). Image courtesy of NTU

However, the e-textile market is slow for various reasons related to both commercialization and design challenges. What are researchers doing to overcome these barriers?

What are e-textiles?

E-textiles refer to fabric or fabric into which electronics are “woven”. Since there are a number of ways to combine textiles with electronics, e-textiles can be divided into a number of categories: embedded e-textiles, laminated e-textiles, smart textiles, and smart fabrics, to name a few.

This article focuses on e-textiles, especially in medical applications, where the circuit is integrated in whole or in part into the fabric, thereby affecting the ability to collect sensor data.

An example of embedding technology in fabric.

An example of the embedding of technology in the fabric. Image courtesy of Shi et al. and Fudan University

With the help of sensors, e-textiles can observe biometric data for fitness assessment, continuously monitor chronic diseases and provide and receive feedback from medical professionals without going to the clinic.

E-textiles can be beneficial in healthcare for medical diagnosis and monitoring of clinical conditions, especially telemedicine. In a previous article, e-textiles were even tested for use in hospital bedsheets to monitor patients.

Barriers to Commercialization

Several companies are currently working on e-textile products, including Apple, Adidas AG, Fujitsu Limited, Fibretronic and Interactive Wear AG.

Some of the challenges that stand in the way of e-textiles commercialization are flexible hybrid electronics, conductive fibers, power generation techniques, materials science, interference shielding, and manufacturability.

These problems can be difficult for electrical engineers to solve. Most EEs are used to rigid circuit boards, reliable manufacturing processes, and silicon-based materials.

Reliability and security aspects

Textile cables used to connect media for signal connection must be safe, sturdy, and durable. Reliability is an issue for wearable technology and e-textiles. These devices must not be affected by hostile environments such as rain, snow, high humidity, and even washing.

Another problem is a reliable power supply. One way e-textile research can address this is through energy harvesting technology. Other important design considerations are higher power density, simple charging solutions, and high isolation.

A washable e-textile display for medical purposes

While designing e-textiles for garments and everyday wear may be a long way off, this technology holds great promise in healthcare and medical research. A group of researchers recently developed a type of e-textile that is capable of communicating, sensing, and powering an illuminating display unit.

The researchers claim to have produced the power supply for the integrated textile system from battery fibers that store energy from the photovoltaic textile module. They wove photoanode shots with silver-plated conductive yarn for solar energy.

By integrating the chains and wefts in battery fibers made of flexible MnO2-coated carbon nanotube fibers (cathode), zinc wire (anode) and ZnSO4 gel electrolytes, the researchers were able to demonstrate both power generation and storage in the textile. The researchers also say the fabric is washable, which is vital to the commercialization of e-textiles.

Demonstration of the energy harvesting and storage module for e-textiles.

Demonstration of the energy harvesting and storage module for e-textiles. Image courtesy of Shi et al. and Fudan University

When weaving the textile display, the researchers used devices that were powered by the electric field of the ZnS phosphor. They also suggest that such devices only need spatial contacts between weft and warp threads to illuminate what makes the fibers inherently durable and suitable for large-scale production.

A diagram of the process used to make this type of e-textile.

A diagram of how this type of e-textile material is made. Image courtesy of Shi et al. and Fudan University

They also designed a textile keyboard by weaving a low-resistance warp (silver-plated thread) with a high-resistance weft.

This system is designed for people with speech or language difficulties. The display systems can display a generic keyword about a person’s mental state after decoding electroencephalogram signals.

Decoding of the mental state from electroencephalogram signals.

Decoding of the mental state from electroencephalogram signals. Image courtesy of Shi et al. and Fudan University

A disadvantage of this innovation is that it can be unsafe for practical use as the power supply must be below 36V.

The slow (but promising) future for e-textiles

From the point of view of user friendliness and product design, e-textiles still seem a long way off from widespread acceptance. However, with leading brands and even the military investing in e-textile development, this technology could one day move out of a predominantly academic environment.

It is also likely that the commercialization of e-textiles will require a strengthened supply chain and an awareness among engineers and suppliers of the challenges of systems integration. These devices must also be optimized through regulatory approvals in order to be launched.

While e-textiles are unlikely to become a common electronic product in households, in the medical setting, as research – like that of Fudan University – increases, they may appear more easily.

Find out about other e-textile research

There is a lot of research going on in e-textiles and smart clothing. Check out some of the latest developments below.

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