Asia-Pacific Biotech News

Powering Electronics Through Wearable Texiles

Researchers have developed a textile that can convert the wearer’s body movement into electricity and be used to power wearable devices.  

From smartwatches to biomedical sensors, wearable technologies are starting to become commonplace in society. Their popularity can be attributed to their multi-functionality, artificial intelligence support, and portability, which allow them to have a multitude of applications ranging from health and fitness monitoring to entertainment and disability aids.

At present, one of the biggest challenges in wearable technology is its dependence on lithium batteries. Since wearable electronics demand lightness, comfort, and flexibility, the battery attached to them has to be small in size. As a result, battery power tends to be compromised, and the consequent reduced lifespan means that wearable electronics need to be taken off regularly for charging. This has enormous implications for their application as disability aids and wearable medical devices, as these devices have to be continuously worn. In addition, the chemical contents of batteries are toxic. As such, their disposal, recycling, or reuse processes have to be closely monitored to prevent potential environmental pollution problems. Hence, great effort has been put into developing a more effective and sustainable energy harvesting method for wearable technology.

Conventional, environmentally friendly energy-harvesting technology includes solar and thermal harvesting technologies. However, in the case of wearable electronics, it is necessary for the power source to be flexible, portable, and wearable as well. To achieve this, a team of nanoscientists from the Chinese Academy of Sciences, Hefei Normal University, Sichuan University, and the Georgia Institute of Technology have turned towards a curious material as a means for energy source and power supply: textile.

Led by Professor Kai Dong, the team developed an integrated power textile that can provide an efficient route for the sustainable operation of wearable electronics. This integrated power textile has two components: a fibre-based triboelectric nanogenerator (fibre-TENG) and a novel coaxial fibre-shaped supercapacitor (fibre-SC).  

As the name suggests, fibre-TENG is a power generator that works by taking advantage of the triboelectric effect, a process in which electricity is generated when certain materials come into frictional contact with each other. Since the human body is always in motion, TENG integrated into yarns or fabrics can be used to collect and store disordered low-frequency energy from the human body. In addition to a power generator, an energy storing unit is required to produce a functional and self-sustaining energy supply. Hence, the researchers developed a novel fibre-based supercapacitor (fibre-SC) that can be used to collect and store the pulse energy created by fibre-TENG. The combined textiles can be arranged in specific conformations to produce the necessary operating voltages and output currents. 

The device shows great promise for delivering wearable energy generation and storage. For starters, the use of common yarn and fabrics is advantageous as they are low in cost, flexible, wearable, and easy to mass produce. In addition, the device is practical for day-to-day use as the specific outer coating of the device allows it to be washable. With regards to their capacity as a power supply, their use of supercapacitors is especially notable, as supercapacitors have a higher power density, faster charging rates, and longer cycle life as compared to conventional batteries.  

The authors concede that more fine-tuning is required before the device can be manufactured for commercial use. Specifically, more research needs to be carried out to optimise the design and fabrication process of the power textile, especially since fibre-TENG is prone to complex deformation and mechanical stresses. Overall, the flexible yarn structures of fibre-TENG and fibre-SC and their integration into textiles provide great application prospects as a sustainable self-charging energy supply for wearable electronics in the future. [APBN]

Source: Sheng et al. (2023). Wearable energy harvesting-storage hybrid textiles as on-body self-charging power systems. Nano Research Energy, 1–10. https://doi.org/10.26599/NRE.2023.9120079