A flexible wearable sensor based on improving the piezoelectric layer performance of sandwich structures with micro-/mesopores for communication with the deaf-mute

Abstract

Layered H-UiO-66@IL composites with both intraparticle micropores, interparticle mesopores, and multiple active sites were prepared. A key aspect of the technique was the addition of deionized water during solvothermal synthesis, which rapidly nucleated layered nanoparticles. A multifunctional, flexible, and stable polyacrylonitrile (PAN)-based membrane was successfully constructed by incorporating H-UiO-66 nanoparticles, modified by ionic liquid (1-allyl-3-butylimidazole tetrafluoroborate), into polymers with macromolecular chains under mild, controlled conditions. The resulting film exhibited excellent dielectric, ferroelectric, and mechanical properties due to the multilayer fiber design. Furthermore, the PAN matrix showed a higher content (97.41%) of planar zigzag conformations, enhancing the piezoelectric properties. The composite film demonstrated ultra-high sensitivity (10.98 V/N) and an ultra-low detection limit of 3.5 × 10⁻⁴ N. In addition, the film passed 1,800-cycle stability tests and maintained its initial output value across various environmental conditions. This flexible piezoelectric sensor shows significant potential for aiding deaf and mute individuals in sign language or breathing communication.