Stretchy, see-through touch panel made from salt-packed hydrogel

Touch panels of the future will be a lot like Olympic gymnasts—flexible, stretchy, and resilient. With these properties, touch panels can hug the human form like a leotard, letting us wear electronic devices rather than stick them in our pockets, purses, or briefcases. To date, however, most touch panels have been built with materials that resist stretching, such as indium tin oxide and carbon nanotubes. Researchers at Seoul National University now report a transparent touch panel that can be stretched to 10 times as large as its original area without losing functionality (Science 2016, DOI: 10.1126/science.aaf8810). The superstretchy, see-through device is made of a polyacrylamide hydrogel containing lithium chloride salts. Because of the high water content of the hydrogel, the salt dissolves and acts as an ionic conductor. The scientists who developed the technology, led by Jeong-Yun Sun, made an arm-hugging touch panel and used it for writing and playing video games. Perhaps by the time the 2020 Olympics roll around, we’ll be able to watch gymnasts write notes to their fans during downtime with touch panels embedded in their leotards.