It’s time to roll up your sleeves for the next advancement in wearable technology: a fabric armband that’s actually a touch pad. In ACS NanoResearchers say they’ve developed a way to make playing video games, sketching cartoons and signing documents easier. Their proving silk armband turns a person’s forearm into a keyboard or sketchbook. The three-layer, touch-responsive material interprets what the user draws or prints and turns it into images on the computer.
Computer trackpads and electronic signature recording devices seem to be everywhere, but they are not as widely used in wearable devices. Researchers have proposed making flexible panels that respond to touch from simple, electrically conductive hydrogels, but the materials are sticky, making them difficult to write on and irritating to the skin. So Xueji Zhang, Lijun Qu, Mingwei Tian and colleagues wanted to incorporate a similar hydrogel into a comfortable fabric sleeve for drawing or playing computer games.
The researchers sandwiched a pressure-sensitive hydrogel between layers of knitted silk. The top cloth was coated with graphene nanosheets to make the fabric electrically conductive. Connecting the sensing panel to the electrodes and data acquisition system created a pressure-responsive pad that quickly sensed in real time when a finger slid across it, writing numbers and letters. The device was then placed in an arm-length silk sleeve with a touch-responsive area on the forearm. During the tests, the user controlled the direction of the blocks in the computer game and drew colorful cartoons in the computer drawing program from the armband. The researchers say their proof-of-concept wearable touch pad could inspire the next generation of flexible keyboards and wearable sketchpads.