Batteries tend to be the bulkiest component in wearables and are often integrated into devices, making them difficult to reclaim – but textiles are emerging as a promising substrate to offer a power source. In collaboration with the Swedish Textile School in Borås, researchers at Chalmers University of Technology have developed a fabric that converts kinetic energy into electrical power. The woven textile is made of piezoelectric yarns that generate electricity when stretched or exposed to pressure, and conductive yarns to transport the electric current, which can currently produce enough energy to work an LED light, pocket calculator or digital watch. Meanwhile researchers at the National Chung Hsing University (Taiwan) and the Georgia Institute of Technology (USA) developed the first energy-harvesting triboelectric fabric that is both waterproof and capable of converting kinetic energy – whether from wind, rain or body movement. Triboelectricity is the charge generated by friction, and up until now, the presence of water would inhibit the effect. The material could therefore be used in flags, tents and roof coverings, as well as umbrellas and raincoats, to power electronic devices when outdoors.
Researchers at the University of Colorado are developing a new type of flexible and self-healing electronic skin that is fully recyclable. Embedded with sensors to measure pressure, temperature, humidity, and air flow, the thin, translucent material mimics the mechanical properties of human skin and could find applications in robotics, prosthetics and biomedical devices, as well as the potential for use in skin grafts and transplants. The e-skin is based on a newly-developed polymer called "polyimine", doped with silver nanoparticles to improve mechanical strength, chemical stability and electrical conductivity. If damaged, a solution of commercially available compounds in ethanol can be administered to heal the “wound”. Once it has reached the end of life, the skin can be soaked in a recycling solution to degrade the polymers, while the silver nanoparticles sink to the bottom. Both the recycled solution and nanoparticles can then be reused to make new, functional e-skin – thereby creating no e-waste and offering a new circular vision for electronics.
Wearables can also help to support and sustain our lives. Millions of diabetics worldwide currently monitor their glucose levels through routine finger-prick testing to obtain a sample of blood. Now however non-invasive, needle-free continuous glucose monitors are increasingly becoming available. SugarBEAT for example is a disposable adhesive patch system that connects to a smartphone app via bluetooth and displays glucose readings every five minutes. In the workplace, wearables are being used to reduce and prevent injuries: from proximity sensors to alert workers if they get too close to powerful machinery, to body monitoring devices like the Kinetic Reflex that detects and offers feedback on high-risk postures and motions, which over time can improve the wearer’s biomechanics. Tech and the elderly may not sound like a natural pairing but smart aging devices can make life easier for senior citizens, and in turn their carers, by giving them more independence. These wearables offer remote healthcare by keeping track of user location, heart rate and/or other vital signs, using this data to flag any abnormalities or emergencies.
As wearables become more purposeful and user-centred, there will be less room for gimmicky gadgets, and with greater awareness of e-waste, devices should be designed using appropriate materials in a way that they can be disassembled easily. Hopefully in the not-so-distant future we’ll start seeing wearables powered via clothing made of recyclable energy-harvesting textiles, enhancing the quality of our lives as well as that of our surroundings.
Next instalment: Collaboration – incubators, open innovation and partnerships.
Written by Mairi Hare as part of a collaboration between Sourcebook GmbH and Texpertise Network.
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