Bioinspired Self-Adaptive Conformal Electronic Armor, Electronic Tattoo and iFlexSense Skin

Conformability plays a ballast role in the final functionality and performance of flexible electronics since it is the basis of superior signal-to-noise ratio and large area mapping capability. It involves flexibility and stretchability, which depends on key factors such as geometry, material, and surface curvature. The interfacial mechanics and adhesion strength at the interfaces determine the nature of this contact. However, conformable integration of flexible electronics on complex 3D surfaces remains to be challenging and costly both from a design and manufacturing perspective.<br/>Bioinspiration has been proved powerful and effective to develop novel materials, devices, and structures from biological systems and biological evolution and refinement which has occurred over millions of years. Historically, many great ideas in science and technology often arise from studying nature. Bioinspired flexible electronics have been widely investigated, the imitated objects range from plants to animals or human, from birds to reptiles, and from terrestrial species to marine species. This presentation mainly introduces bioinspired strategies to design the flexible electronics:<br/>1) <b>Bioinspired Electronic Armor</b>: Bionspired by freeform snakeskin composed of rigid scales and connective soft integument, we propose a novel rigid-structure-based electronic armor (E-armor) that reconciles the protectability and conformability while enables stable electronic functions. It can render the rigid, non-stretchable devices fully conformable to arbitrary 3D surfaces. Based on the unique soft-hinge Kirigami regime, it can make use of the supernormal mechanical advantages like auxetic stretchability and high fill factor but overcome the inherent buckling conflict, rendering the stiff, non-stretchable electronics fully conform to arbitrary 3D surfaces. Meanwhile, the conductivity of soft nodes endows the Kiri-MM with electrical connotation and innovative functionalities. The results establish new directions for applied and basic research in the fields of flexible electronics and soft robotics, with relevance to grant challenges in improving the survivability of flexible electronics in complex environments.<br/>2) <b>Bioinspired Electronic Tattoo</b>: Bioinspired by the breathable human skin, we have successfully designed, fabricated, compensated, and applied a substrate-free tattoo-like electrode system for large-scale epidermal electrophysiology. Highly stretchable and high-area filling-factor electrodes are designed using Peano curves with transformable topology. The breathability of the substrate-free epidermal electrodes is quantified through thermal and hydration characterizations. Applications of these electrodes include multichannel ECG, accurate ASL recognition, and prostheses control, as well as mapping of neck activities. These low-cost but large-area and high-performance epidermal electrodes have paved the way for future large-area epidermal electronics necessary for personnel health/performance management, disease diagnosis, and human-machine interaction.<br/>3) <b>Bioinspired iFlexSense Skin</b>: Bioinspired by the unprecedented sensing abilities (skin, synapse, immune system, and brain) of flying creatures, we innovatively propose an intelligent flexible sensing skin with multifunctional sensor array, data transmission, impact monitoring and artificial intelligence for aerodynamic measurement of complex surface. The skin-like mechanosensation system integrates with five kinds of flexible sensors, including capacitive sensors, piezoelectric sensors, hot-film sensors, temperature sensors, and strain sensors. The synapse-like encoding system is also directly integrated on the sensing skin to convert analog data to digital data to diminish the transmission noise. The brain-like intelligent algorithm is employed to for analyzing the data and making a judgment, such as identifying and localizing the impacts.