Optimization model for flexible piezoelectric film in self-powered pressure sensor

Versatile self-assembled electrospun micropyramid arrays for high-performance on-skin devices with minimal sensory interference

“…3a ). In contrast to micropyramids prepared via previous technologies such as photolithography and 3D printing 8 , 10 , 13 , 25 – 27 , 29 – 31 , the electrospun micropyramids have a gas-permeable network structure consisting of bead-on-string micro/nanofibers (Fig. 2a-I and Supplementary Fig.…”

“…The performance enhancement effects of micropyramids due to their gradient space-filling, gradient stress distribution, and gradient refractive index have been demonstrated, which bring about advanced optical, thermal, mechanical, and electrical properties 7 – 10 , 13 , 25 – 31 , 45 , 48 – 50 . Similarly, EMPA-based on-skin devices exhibit high performance in various application fields, such as daytime radiative cooling, pressure sensing, and bioenergy harvesting.…”

“…Limited by current technologies, especially the random spinning-deposition manner of electrospinning, the functional surfaces of reported imperceptible films are flat planes 5 , 23 , 24 . Because of the inferior optical, thermal, mechanical, and electrical properties of flat planes, endowing imperceptible on-skin devices with outstanding performance is difficult, restricting their application in many fields 9 , 10 , 25 , 26 . In contrast, three-dimensional (3D) microstructure arrays with gradient geometries, for example, micropyramid, microcone, microdome, and microprism arrays, have an edge in developing high-performance devices.…”

“…In contrast, three-dimensional (3D) microstructure arrays with gradient geometries, for example, micropyramid, microcone, microdome, and microprism arrays, have an edge in developing high-performance devices. The reason is that their inherent features of gradient space filling, gradient stress distribution, and gradient refractive index are beneficial for regulating force, heat, light, and electricity 8 – 10 , 13 , 25 – 28 . However, existing 3D microarray processing technologies such as photolithography and 3D printing fail to simultaneously realize high gas permeability, ultralow thickness, ultralight weight, and gradient geometry 8 , 10 , 13 , 25 – 27 , 29 – 34 .…”

“…The reason is that their inherent features of gradient space filling, gradient stress distribution, and gradient refractive index are beneficial for regulating force, heat, light, and electricity 8 – 10 , 13 , 25 – 28 . However, existing 3D microarray processing technologies such as photolithography and 3D printing fail to simultaneously realize high gas permeability, ultralow thickness, ultralight weight, and gradient geometry 8 , 10 , 13 , 25 – 27 , 29 – 34 . The challenge, consequently, is to create a new type of 3D microstructure array with both a gradient geometry and a gas-permeable, ultrathin, ultralight structure to provide various imperceptible on-skin devices with superior performance.…”