3D Printed Electronic Skin for Strain, Pressure and Temperature Sensing

Electronic skin, or e-skin, is an innovative material designed to emulate human skin's flexibility and stretchability. With its capability to detect environmental changes like pressure, temperature, and humidity, it has the potential to revolutionize fields such as robotics, wearable technology, and healthcare. Nevertheless, developing e-skin poses significant challenges: creating durable materials with skin-like flexibility, integrating biosensing abilities, and using advanced fabrication techniques like 3D printing for wearable or implantable applications. To overcome these hurdles, we have fabricated a 3D-printed electronic skin utilizing a novel class of nanoengineered hydrogels with tunable electronic and thermal biosensing capabilities. Our methodology takes advantage of shear-thinning behaviour in hydrogel precursors, allowing us to construct intricate 2D and 3D electronic structures. We simulate the elasticity of skin using triple crosslinking in a robust fungal exopolysaccharide, pullulan, while defect-rich 2D molybdenum disulfide (MoS₂) nanoassemblies ensure high electrical conductivity. The addition of polydopamine (PDA) nanoparticles enhances adhesion to wet tissue. Our nanoengineered hydrogel exhibits outstanding flexibility, stretchability, adhesion, mouldability, and electrical conductivity. A distinctive feature of this technology is the precise detection of dynamic changes in strain, pressure, and temperature enabled by the combination of triple crosslinking and defect-rich MoS₂. As a human motion tracker, phonatory-recognition platform, flexible touchpad, and thermometer, this technology represents a breakthrough in flexible wearable skins and holds transformative potential for the future of robotics and human-machine interfaces.