Electrochromic Pressure-Sensitive Device for In Situ and Instantaneous Pressure Visualization

High sensitivity and spatial recognition of pressure sensors are important for application of the sensors in electronic skins, and in situ visualization is a practical and effective approach to identifying pressure information. Here, we present a facial strategy to achieve in situ pressure information recognition that is visible to the naked eye in coloring form by designing an H₃PO₄/PVA film with hemispheric microstructures in an integrated electrochromic pressure sensor. The device can be applied for different stress scenarios within the range of 0-250 kPa by adjusting the spacing of hemispheric microstructures and can identify the magnitude, position, shape, and duration of the pressure. Furthermore, the device can be used repeatedly by erasing under a 1 V bias, and more obvious information can be displayed under strong sunlight compared with light-emitting equipment. This strategy provides new insight into the design of flexible electronics for in situ and instantaneous pressure visualization in the future.