Exogenous grit adherent to the surface of food items and food fracture properties have each been considered important factors contributing to pattern and degree of tooth wear in mammals. However, the interactions between these two factors in generating distinctive microwear textures have remained understudied. Here the authors revisit in‐vitro results from simulated chewing to explore how adherent grit and physical properties of foods act together to create dental microwear textures on occlusal enamel surfaces. Results suggest that the effect of exogenous grit on microwear texture is dependent on the material properties foods to which they adhere. Grit in the absence of food causes more complex microwear surface textures than foods covered with similar levels and types of grit (for a given number of chews and angle of approach between opposing teeth). Different foods covered in grit also yield different complexity values. Grit‐laden, pliant meat, for example, results in a less complex texture than does resistant, grit‐laden raw carrot. This work implied that tooth wear assessment can benefit from considering grit load and food material properties together.

Additive manufacturing enables the 3D printing of various soft matter structures. Achieving the integrated printing of multicomposition 3D structures, such as ear-like structures containing both hard and soft tissue, has become a research hotspot. However, current multicomposition 3D printing technology still faces numerous challenges, including limited material selection, difficulties in achieving precise transitions between multimodulus regions, and issues with printing accuracy and stability for low-viscosity and fast-curing materials. This study modified Ecoflex by incorporating nanosilica particles and developed a series of Ecoflex/nanosilica composite (ESC) ink formulations suitable for multicomposition 3D printing. The rheological and mechanical properties of ESC inks were thoroughly evaluated, and the weight percentage of nanosilica particles in different Ecoflex types was optimized to identify the most effective formulation. Additionally, 3D printing process parameters were refined to enhance printing accuracy, facilitating the multicomposition printing of complex 3D structures such as hollow columns, nose-like structures, and ear-like structures. These inks were further utilized to print stretchable electronic substrates with strain-isolating properties, and their performance was validated through experimental studies and simulations. The results confirm that the developed ink provides robust technical support for multicomposition 3D integrated printing of stretchable electronics.

Pore size is critical to the oil-storage performance and tribological properties of porous polyimide (PPI). To study the effect of pore size, four PPIs with different pore sizes and similar porosities were fabricated. The mechanical, oil-absorption, and tribological properties of the PPIs were investigated. According to the results, PPIs with larger pores demonstrate faster oil absorption and a higher oil-filling rate. However, larger pores contribute to a rougher surface and lower oil retention. These dual effects result in PPIs with larger pores displaying a low friction coefficient at low speeds but a high friction coefficient at high speeds. The effect of pore sizes on elastohydrodynamic (EHD) film and Stribeck curves were discussed from seepage effect and viscoelasticity of PPI, respectively. The permeability of the four PPIs was calculated based on mercury intrusion test results. Larger pores lead to higher permeability of PPI at lower pressure, which makes it easier to reduce thickness of EHD film, causing high friction and wear. The damping effect of PPIs, rather than a viscous flow, results in a slight increase in friction coefficient at high speed under micro-oil lubrication. Considering the tribological and oil-absorption properties, the preferred particle size of polyimide molding powder is 25–48 μm.

Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention. In this study, we report a TiO₂-based nanowire (TiO₂NWs) scaffolds, which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles. It is found that the elastic and adhesive forces in the TiO₂NWs scaffolds can increase significantly after multiple cycles of nano-deformation. Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO₂NWs scaffolds. These properties allow the TiO₂NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future.