Excellent broadband sound absorption in composites manufactured by embedding piezoelectric polymer aerogels in porous ceramics.

Challenges remain in the design and manufacture of acoustic devices with excellent broadband sound absorption performance. Herein, an efficient acoustic absorber with hierarchical pore structure and additional acoustic-electrical energy conversion mechanism is reported in which combined zirconia porous ceramics and P(VDF-TrFE) piezoelectric aerogels. Reticular cross-scale pore structure enables sound waves to propagate and dissipate effectively.

Thermoplastic PHB-Reinforced Chitosan Piezoelectric Films for Biodegradable Pressure Sensors.

Flexible and wearable pressure sensors have attracted significant attention in the fields of smart medicine and human health monitoring. Nevertheless, the design and fabrication of degradable disposable pressure sensors still face urgent challenges. Herein, we fabricated poly(3-hydroxybutyrate) (PHB)-reinforced chitosan (CS) piezoelectric films for intelligent sensors through a simple, low-cost, and environmentally friendly roll-forming method.

Tristate Photonic Crystal Film with Structural, Fluorescent, and Up-Conversion Luminescent Color for Multilevel Anticounterfeiting.

Counterfeit items are growing worldwide, affecting the global economy and human health. Anticounterfeiting tags based on a physical microstructure or chemical materials have enjoyed long-term commercial success due to their visualization and inexpensive production. However, conventional anticounterfeiting tags can be readily imitated.

A Directional Chitosan Sound Sensor Based on Piezoelectric-Triboelectric Sensing.

Herein, we have constructed a directional sound sensor based on an anisotropic chitosan aerogel. Because of the lamellar porous structure, this chitosan aerogel exhibits a distinct anisotropic behavior, featuring the compressive stress along the direction of the parallel laminate structure, being approximately 2.6 times that in the orthogonal direction.