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Nature is endless inspiration for the design of many extraordinary things that enables many new developments from bird-inspired airplanes to bio-robotics. However, biological structures are usually not designed to carry high mechanical loads in extreme conditions such as high strength fan blades in aero-engines. The insufficient mechanical strength limits the application of bio-inspired materials. On the contrary, metallic alloys are widely used for high performance applications involving extreme environmental conditions ranging from high temperatures in aero-engines to high pressure in deep ocean. However, the properties of metallic alloys are not sufficiently adaptive in response to the environmental changes as bio-materials. In this talk, I will demonstrate that it is possible to design architected materials that not only have high strength, but also have adapting ability thanks to the mimicry of crystal microstructure. The crystal-inspired approach enables the employment of the hardening mechanisms of alloys to design extremely lightweight materials with extraordinary strength and truly damage tolerance while offering unprecedented opportunities to tailor the mechanical properties of meta-materials [1]. The mimicry of crystal microstructure leads to a new class of meta-materials (meta-crystals) containing hierarchical and tunable structures across multiple scales from nm to mm and beyond. I will demonstrate that we can readily change crystal-inspired meso-structures (via computer-aided design) and the intrinsic microstructure of materials by using multi-materials and tailoring the process parameters. I will show new ways to store, communicate, sense and actuate certain functionalities in meta-materials. Various materials (including high strength alloys Ti6Al4V, Inconel 718) were used to fabricate new meta-crystals by additive manufacturing (such as laser powder bed fusion) to study the behaviour and realise the potential of adaptive meta-crystals.
References
[1] Pham M-S, Liu C, Todd I, Lertthanasarn J. Damage-tolerant architected materials inspired by crystal microstructure. Nature 2019;565:305.
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