Gecko-Inspired Paper Artificial Skin for Intimate Skin Contact and Multisensing

Touch sensing is the most basic but important way for organisms to interact with the outside world, and thus, fingertip skin has been widely studied to enable the manufacture of artificial skin. Sensitive multisensing integrated with perfect adhesion performance is crucial for synchronous and sensitive human physical and biochemical indicator monitoring. Here, a gecko-inspired nanotentacle skin integrated with a microfluidic system and a polyvinylidene fluoride (PVDF)-based piezoelectricity nanogenerator (PENG) is proposed for simultaneous multisensing. The obtained 3D nitrocellulose (NC) nanotentacle array paper is flexible and freestanding. Stainless stamps are used to imprint lithography patterns (microfluidic channels) on the NC paper, and channels with three branches are used for sweat split-flow and sensing of pH, urea, and lactic acid. Meanwhile, the patterned substrate is integrated with a PENG, and the nanotentacles allow the substrate to conformally fit to rough skin, thus enabling sensitive sensing of micromotions (pulse beats). The results indicate that the multifunctional skin sensor is capable of sensitively monitoring the human state, thereby serving as an inspiring example for the construction of next-generation skin with smart sensing systems. Furthermore, our sensors are amenable to a variety of applications, such as personal care, artificial skin, and human-machine interactions.