Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong 999077, China.
Department of Aeronautical and Aviation Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong 999077, China.
ACS Nano. 2023 Mar 28;17(6):5921-5934. doi: 10.1021/acsnano.3c00015. Epub 2023 Mar 15.
Following earlier research efforts dedicated to the realization of multifunctional sensing, recent developments of artificial skins endeavor to go beyond human sensory functions by integrating interactive visualization of strain and pressure stimuli. Inspired by the microcracked structure of spider slit organs and the mechanochromic mechanism of chameleons, this work aims to design a flexible optical/electrical skin (OE-skin) capable of responding to complex stimuli with interactive feedback of human-readable structural colors. The OE-skin consists of an ionic electrode combined with an elastomer dielectric layer, a chromotropic layer containing photonic crystals and a conductive carbon nanotube/MXene layer. The electrode/dielectric layers function as a capacitive pressure sensor. The mechanochromic photonic crystals of ferroferric oxide-carbon magnetic arrays embedded in the gelatin/polyacrylamide stretchable hydrogel film perceive strain and pressure stimuli with bright color switching outputs in the full visible spectrum. The underlying microcracked conductive layer is devoted to ultrasensitive strain sensing with a gauge factor of 191.8. The multilayered OE-skin delivers an ultrafast, accurate response for capacitive pressure sensing with a detection limit of 75 Pa and long-term stability of 5000 cycles, while visualizing complex deformations in the form of high-resolution spatial colors. These findings offer deep insights into the rational design of OE-skins as multifunctional sensing devices.
在早期致力于实现多功能传感的研究努力之后，最近的人工皮肤研究进展通过整合应变和压力刺激的交互式可视化，努力超越人类的感官功能。受蜘蛛狭缝器官的微裂纹结构和变色龙的机械变色机制的启发，本工作旨在设计一种灵活的光电皮肤（OE-皮肤），它能够对复杂刺激做出响应，并具有交互式的人眼可读结构色反馈。OE-皮肤由一个离子电极与一个弹性体介电层、一个含有光子晶体的变色层和一个导电碳纳米管/MXene 层组成。电极/介电层充当电容式压力传感器。嵌入在明胶/聚丙烯酰胺可拉伸水凝胶薄膜中的氧化铁-碳磁阵列的机械变色光子晶体感知应变和压力刺激，在整个可见光谱中具有明亮的颜色切换输出。底层的微裂纹导电层用于超灵敏应变传感，其应变系数为 191.8。多层 OE-皮肤可实现超快速、准确的电容压力感应响应，检测限为 75 Pa，循环稳定性为 5000 次，同时以高分辨率空间颜色的形式可视化复杂变形。这些发现为 OE-皮肤作为多功能传感设备的合理设计提供了深刻的见解。
