Electronic skin, or e-skin, may play a vital role in upcoming next-generation personalized medicine, prosthetics, robotics, and more. Scientists from King Abdullah University of Science and Technology have developed a durable e-skin capable of sensing objects from 20cm away, responding to stimuli in less than one-tenth of a second, and when used as a pressure sensor, could distinguish handwriting written upon it. Such e-skins could monitor a variety of biological information, such as blood pressure changes, which can then be shared and stored via Wi-Fi.
To create their state-of-the-art e-skin, the team used a hydrogel reinforced with silica nanoparticles as a strong and stretchy substrate and a 2D titanium carbide MXene as the sensing layer, bound together with highly conductive nanowires. By pre-stretching the hydrogel, then applying a layer of nanowires and carefully controlling its release, the team created conductive pathways to the sensor layer that remained intact even when the material was stretched to 28 times its original size.
Currently, most e-skins are made by layering active nanomaterial on a stretchy surface that attaches to the skin. However, the connection between these layers is often too weak, reducing the durability and sensitivity of the material. If it’s too strong, flexibility is limited, making it more likely to crack. However, after 5,000 deformations, the KAUST team’s e-skin continued to work as intended, recovering in about a quarter of a second each time.
