Metric mechanics with nontrivial topology: Actuating irises, cylinders, and evertors
Metric mechanics with nontrivial topology: Actuating irises, cylinders, and evertors
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DOI：
10.1103/physreve.104.065004
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发表时间：
2021-12-20
影响因子：
2.4
通讯作者：
Biggins, J. S.
中科院分区：
文献类型：
--
作者：
Duffy, D.;Javed, M.;Biggins, J. S.
液晶弹性体在加热时沿其导向器沿着收缩，在冷却时恢复，提供了作为致动器和人造肌肉的巨大潜力。如果用空间变化的指向矢图案对平板进行编程，那么它将驱动成曲面，使材料充当强大的机器，如抓取器或升降机。在这里，我们研究的驱动程序的环形片，由于其中心孔，可以回避限制的面积和方向。我们系统地编目的一组可开发的表面编码通过轴对称导演图案和揭示几个定性的新模式的驱动，包括气缸，虹膜，和外翻的表面，其中的内边界成为外边界驱动后。我们确认我们的设计与实验和数值相结合。我们的许多致动器可以在完成致动后重新获得其初始内径或外径，这使得它们特别有前途，因为它们即使在固定到框架或管道上时也可以避免其激活状态下的潜在问题应力。
Liquid crystal elastomers contract along their director on heating and recover on cooling, offering great potential as actuators and artificial muscles. If a flat sheet is programed with a spatially varying director pattern, then it will actuate into a curved surface, allowing the material to act as a strong machine such as a grabber or lifter. Here we study the actuation of programed annular sheets which, owing to their central hole, can sidestep constraints on area and orientation. We systematically catalog the set of developable surfaces encodable via axisymmetric director patterns and uncover several qualitatively new modes of actuation, including cylinders, irises, and everted surfaces in which the inner boundary becomes the outer boundary after actuation. We confirm our designs with a combination of experiments and numerics. Many of our actuators can reattain their initial inner or outer radius upon completing actuation, making them particularly promising, as they can avoid potentially problematic stresses in their activated state even when fixed onto a frame or pipe.