These Rubber-Like Micro-Supercapacitors Keep on Ticking Even When Stretched, Folded, or Wrinkled
Aimed at wearables and robotics systems, these rubbery power storage devices don't care if they get in a twist — literally.
Researchers from the Pohang University of Science and Technology (POSTECH), the Korea Institute of Industrial Technology, and Konkuk University have come up with a new approach to powering wearables and other devices where movement is to be expected: soft, stretchable, rubber-like micro-supercapacitors.
"The use of laser-patterned liquid metal electrodes represents a significant step forward in the development of truly deformable energy storage solutions," Jin Kon Kim, POSTECH professor and co-corresponding author on the paper detailing the devices explains of its novel approach. "As wearable technologies continue to advance, innovations like these will play a vital role in ensuring that our devices can adapt to the demands of our dynamic lifestyles."
The micro-supercapacitors developed by the team use layers of eutectic gallium-indium liquid metal (EGaIn) and graphene that are patterned by laser to create the electrodes — avoiding the use of brittle materials like gold, which don't take well to repeated stretching and twisting. These electrodes are fitted to a stretchable substrate called polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene copolymer, or SEBS, to create the flexible energy-storage devices themselves.
An array of these micro-supercapacitors, the team says, was tested up to 1,000 repeated stretching and relaxing cycles while retaining 90 percent of its capacity for storing energy — while the devices were also put through other torturous tests including folding, twisting, and wrinkling with no major loss in performance.
The team's work has been published in the journal npj Flexible Electronics under open-access terms; no details on commercialization had been disclosed at the time of writing.