Fibre-based electronics are expected to play a vital role in next-generation wearable electronics. Woven into textiles, they can provide higher durability and provide additional features such as sensing to monitor biological signals from the human body, such as pulse and muscle movements. Ideally these fibres can also harvest mechanical energy from the body via bending, stretching, and pressing.
Professor Seungbum Hong and Professor Steve Park from the Department of Materials Science and Engineering and their team (above) fabricated a stretchable fibre with a ferroelectric layer composed of P(VDF-TrFE)/PDMS sandwiched between stretchable electrodes composed of a composite of multi-walled carbon nanotubes (MWCNT) and poly 3,4-ethylenedioxythiophene polystyrenesulfonate (PEDOT:PSS).
Cracks formed in MWCNT/PEDOT:PSS layer help the fibre show high sensitivity compared to previous fibre strain sensors. The new fibre can also harvest mechanical energy under various mechanical stimuli such as stretching, tapping, and injecting water into the fibre using the piezoelectric effect of the P(VDF-TrFE)/PDMS layer.
“This new fibre has various functionalities and makes the device simple and compact. It is a core technology for developing wearable devices with energy harvesting and strain sensing capabilities,” said Professor Hong.
Figure 1.Schematic illustration of an SMF fibre and its piezoelectric voltage output and response to strain.
Figure 2. Photographs of a stretchable multi-functional fiber being stretched by 100%, bent, and twisted.