Bimaterial lattices as thermal adapters and actuators
Bimaterial lattices as thermal adapters and actuators
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DOI：
10.1088/0964-1726/25/11/115030
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发表时间：
2016-10
影响因子：
4.1
通讯作者：
M. Toropova;C. Steeves
中科院分区：
文献类型：
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作者：
M. Toropova;C. Steeves
这篇论文的目的是展示各向异性生物材料晶格如何用于热驱动。与其他具有定制热膨胀的晶格相比，这些双材料晶格的各向异性使其独特地适合用作热执行器。每个单独的电池，以及由这些电池组成的晶格，可以设计成在不同方向上具有非常不同的预定热膨胀系数(CTE)，从而能够实现适合于被动或主动控制的激励的复杂形状变化。晶格由平面不同的单元格组成，每个单元格由一个围绕着不规则三角形的倾斜六边形组成。电池和任何电池的所有成员通过销相互连接，因此它们没有旋转约束，并且能够自由扩展或收缩。在这种情况下，六边形的斜角和两种组成材料的CTE的比率决定了晶格的整体性能。在晶格的边界处，晶格通过引脚连接到衬底，并被配置为使得两个相邻晶格顶点之间的CTE与相邻衬底的CTE重合。如果晶格的边界行为与衬底的热性能相匹配，则结构中的温度变化会产生热应变，而不会产生任何相应的应力。这种晶格可用于三种不同的方式：作为具有不同CTE的部件的无应力连接的自适应元件；用于结构的微调；以及作为热驱动执行器。在这篇文章中，我们演示了格子构型的一些概念，这些格子构型产生热驱动位移，从而使几个执行器：开关、阀门和镊子。
The goal of this paper is to demonstrate how anisotropic biomaterial lattices can be used in thermal actuation. Compared to other lattices with tailored thermal expansion, the anisotropy of these bimaterial lattices makes them uniquely suitable for use as thermal actuators. Each individual cell, and hence lattices consisting of such cells, can be designed with widely different predetermined coefficients of thermal expansion (CTE) in different directions, enabling complex shape changes appropriate for actuation with either passive or active control. The lattices are composed of planar non-identical cells that each consist of a skewed hexagon surrounding an irregular triangle. The cells and all members of any cell are connected to each other by pins so that they have no rotational constraints and are able to expand or contract freely. In this case, the skew angles of the hexagon and the ratio of the CTEs of the two component materials determine the overall performance of the lattice. At its boundaries, the lattice is connected to substrates by pins and configured such that the CTE between two neighboring lattice vertices coincides with the CTE of the adjacent substrate. Provided the boundary behavior of the lattice is matched to the thermal properties of the substrates, temperature changes in the structure produce thermal strains without producing any corresponding stresses. Such lattices can be used in three different ways: as adaptive elements for stress-free connection of components with different CTEs; for fine tuning of structures; and as thermally driven actuators. In this paper, we demonstrate some concepts for lattice configurations that produce thermally-driven displacements that enable several actuators: a switch, a valve and tweezers.