Bionic multifunctional structural materials that are lightweight, strong, and perceptible have shown great promise in sports, medicine, and aerospace applications. However, smart monitoring devices with integrated mechanical protection and piezoelectric induction are limited. Herein, we report a strategy to grow the recyclable and healable piezoelectric Rochelle salt crystals in 3D-printed cuttlebone-inspired structures to form a new composite for reinforcement smart monitoring devices. In addition to its remarkable mechanical and piezoelectric performance, the growth mechanisms, the recyclability, the sensitivity, and repairability of the 3D-printed Rochelle salt cuttlebone composite were studied. Furthermore, the versatility of composite has been explored and applied as smart sensor armor for football players and fall alarm knee pads, focusing on incorporated mechanical reinforcement and electrical self-sensing capabilities with data collection of the magnitude and distribution of impact forces, which offers new ideas for the design of next-generation smart monitoring electronics in sports, military, aerospace, and biomedical engineering.

Collecting fog water is crucial for dry areas since natural moisture and fog are significant sources of freshwater. Sustainable and energy-efficient water collection systems can take a page out of the cactus’s playbook by mimicking its native fog gathering process. Inspired by the unique geometric structure of the cactus spine, we fabricated a bioinspired artificial fog collector consisting of cactus spines featuring barbs of different sizes and angles on the surfaces for water collection and a series of microcavities within microchannels inspired by Nepenthes Alata on the bottom to facilitate water flowing to the reservoir. However, replicating the actual shape of the cactus spine using conventional manufacturing techniques is challenging, and research in this area has faced a limitation in enhancing water-collecting efficiency. Here, we turned to 3D printing technology (vat photopolymerization) to create bio-mimetic fog collectors with a variety of geometric shapes that would allow for the most effective conveyance and gathering of water. Various barb sizes, angles between each barb in a single array, spine and barb arrangements, and quantity of barbs were tested experimentally and numeric analysis was carried out to measure the volume of water collected and optimize the mass rate. The result shows that optimal fog collection is with a mass flow rate of 0.7433 g/min, with L_i = 900 μm, θ = 45°, ϕ = 90°, N_b = 2, and N_s = 5. This study presents a sustainable and ecologically sound method for efficiently collecting humid air, which is expected to be advantageous for the advancement of future-oriented fog-collection, water-transportation, and separation technologies.

Traditional piezoelectric materials, such as lead zirconate titanate (PZT), are widely used due to their superior ability to convert mechanical energy into electrical energy. However, these lead-based ceramics are highly toxic and environmentally hazardous. This report explores Rochelle salt as an eco-friendly alternative, despite its brittleness and lower piezoelectric properties compared to PZT. The study investigates methods to enhance the energy capture of Rochelle salt crystals(RS) by varying crystal volume, impact frequency, and force, as well as by incorporating the 3D-printed biomimetic structure inspired by the pomelo fruit peel, which is naturally optimized for absorbing out-of-plane crushing forces. Experimental crystals grown within this structure were compared with those grown without it, focusing on energy capture and durability. Additionally, units with a 64:36 crystal-to-resin ratio were designed to assess the impact of crystal volume on voltage output. The experiments involved varying impact frequencies (120 rpm and 250 rpm) and compression distances (0.034 and 0.068 inches) using a digital oscilloscope and a custom crank slider mechanism. The results indicate that reducing crystal thickness and increasing rpms enhance voltage capture, suggesting that biomimetic structures can significantly improve the mechanical and electrical performance of piezoelectric materials.