A methodology is presented to manufacture bionic mineralized composites by harnessing guided biomineralization within highly ordered polymer scaffold. The fabrication strategy demonstrates a living material system with exceptional mechanical properties, exhibiting significant difference from existing methods. This research progress highlights an exciting opportunity for future bionic composite materials by tailoring interactions or communications between living organisms and 3D-printed synthetic materials. This paper has been accepted by Advanced Materials recently.

We demonstrate a new paradigm in harnessing bacteria to enable on-demand and autonomous healing of 3D-printed ceramics. Improving the damage tolerance of 3D-printed ceramics has been a long-lasting endeavor. Most of the existing efforts have been devoted to improving the fracture resistance of the constituent materials; however, healing of the damaged 3D-printed ceramics remains largely unexplored. The concept proposed in this project fills this technology gap by using carbonate-precipitating bacteria to heal 3D-printed ceramics (polymer-derived ceramics).

Bacteria-assisted healing of 3D-printed ceramics at room temperature may facilitate in situ or autonomous healing of ceramics with various complex architectures for a wide range of applications, such as in vitro biomedical devices, water treatment membranes, lattice structures, and body armor. Besides, a theoretical model was implemented to understand the healing mechanism. A cohesive zone model (CZM) in ABAQUS was applied to simulate the crack propagation process of the bio-mineralization healed interface.

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Electrophoresis-induced hydrogel adhesion is such a technology that induces electrically-triggered reversible adhesion and may be useful for various engineering applications. Here, we establish an analytical theory framework to model the electrophoresis-induced reversible adhesion. We consider that during the electrophoresis process, free charged chains are driven by the electric field to move across the interface to interpenetrate into the respective material matrix, and form weak ionic bonds with chains with opposite charges.

We model the interpenetration of the charged polymer chains as an electrically-driven diffusion-reaction process. The chain diffusion follows an electrically-driven reptation-like motion, and cationic-anionic bond formation follows a bell-like chemical reaction. Our theoretical results agree well with the experiments for both electrophoresis-induced adhesion and adhesion releasing. We expect our theoretical model may facilitate the quantitative understanding and optimization of various methods for actively controlling the adhesion of soft materials.

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Static tensile experiments and progressive failure simulations of single-bolt, single- and double-lap joints were carried out to comparatively investigate secondary bending effects, which present significant eccentric-loading phenomena in single-lap joints but are almost non-existent in symmetric double-lap joints.

Progressive damage models of single-lap and double-lap joints were established, from which the numerical predictions were found to be in good agreement with the experimental outcomes. Experimental macro-scope failure patterns and seven numerical micro-scope failure modes obtained from the progressive damage analyses were presented for the joints.

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