Wearable electronic devices can be integrated into textiles. To be worn comfortably, the devices and their power supplies need to be flexible. So-called triboelectric nanogenerators (TENGs) can convert the energy from movement into electricity and are promising for applications in wearable electronics.

Junyi Zhai, Weiguo Hu, Beijing Institute of Nanoenergy and Nanosystems and National Center for Nanoscience and Technology (NCNST), Beijing, China, Zhong Lin Wang, Beijing Institute of Nanoenergy and Nanosystems, NCNST, and Georgia Institute of Technology, Atlanta, USA, and colleagues have developed a yarn which can serve as a TENG and that can easily be processed in the textile industry. The yarn has a core consisting of conductive stainless steel fibers and a shell made from dielectric Spandex fibers. It can be weaved or knitted like other yarns, and the resulting fabrics are machine-washable.

The researchers tested textiles made from the developed material in socks (under the foot) and T-shirts (under the arm) and were able to harvest energy during movements such as walking or running. The energy was sufficient to power, e.g., a watch.

• Core–Shell-Yarn-Based Triboelectric Nanogenerator Textiles as Power Cloths,
  Aifang Yu, Xiong Pu, Rongmei Wen, Mengmeng Liu, Tao Zhou, Ke Zhang, Yang Zhang, Junyi Zhai, Weiguo Hu, Zhong Lin Wang,
  ACS Nano 2017.
  https://doi.org/10.1021/acsnano.7b07534