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

Electronic skin (E-skin) that can mimic the flexibility and stretchability of human skin with sensing capabilities, holds transformative potential in robotics, wearable technology, and healthcare. However, developing E-skin poses significant challenges such as creating durable materials with skin-like flexibility, integrating biosensing abilities, and using advanced fabrication techniques 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 behavior 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 nanoparticles enhances adhesion to wet tissue. The 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. 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.