Wearable electronics are becoming more popular not just in the consumer market, but also as medical devices. They do have some issues just like other electronic devices – they are mostly made from toxic, non-environmentally friendly materials. Now scientists at the Chalmers University of Technology and the Wallenberg Wood Science Center have created simple electronic textiles that can be manufactured in traditional ways.
This invention takes advantage of cellulose thread, which is conductive and can be sewn into fabric using a standard household sewing machine. The biggest advantage of cellulose thread is that it is thermoelectric – it produces a small amount of electricity when it is heated on one side. Human body can be that source of heat – human body temperature allows this fabric to generate around 0.2 microwatts of electricity, which could be enough for a medical sensor.
Cellulose normally is not very conductive. However, scientists dyed it with an electrically conductive polymeric material, which gives it record high conductivity. It could, however, be further improved with silver nanowires. Scientists say that this material is relatively durable – its properties remain after several wash cycles. But what could we do with a conductive fabric?
It could become the basis for wearable electronics. These materials – cotton and cellulose – are green, easy to recycle and biodegradable. This fabric could serve as a circuit board for some devices, particularly medical wearables, designed to monitor some conditions. For example, conductive cellulose thread could be sewn into bandages that monitor healing of the wound.
Christian Müller, research leader of the study, said: “Cellulose is a fantastic material that can be sustainably extracted and recycled, and we will see it used more and more in the future. And when products are made of uniform material, or as few materials as possible, the recycling process becomes much easier and more effective”.
Cellulose is a natural organic material. A lot of cellulose is in cotton (90 %), wood (40-50 %), hemp (57 %). It is relatively easy to harvest and we are already using a lot of it. This should make the conductive cellulose industry easy to establish.
Wearable electronics are likely to become more popular in the near future. They can help tracking your athletic performance, improve your lifestyle choices, monitor the environment you’re in and your health parameters. The problem is that our devices get old quick and we produce a lot of e-waste. Hopefully, natural fabrics can help reduce the environmental impact of our consumerism regarding wearable electronics.
Source: Chalmers University of Technology