Elastohydrodynamics of a pre-stretched finite elastic sheet lubricated by a thin viscous film with application to microfluidic soft actuators
Elastohydrodynamics of a pre-stretched finite elastic sheet lubricated by a thin viscous film with application to microfluidic soft actuators
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由薄粘性薄膜润滑的预拉伸有限弹性片的弹性流体动力学及其在微流体软执行器中的应用
DOI：
10.1017/jfm.2018.967
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发表时间：
2017
影响因子：
3.7
通讯作者：
M. Bercovici
中科院分区：
文献类型：
--
作者：
E. Boyko;R. Eshel;K. Gommed;A. Gat;M. Bercovici
粘性薄膜与弹性薄片的相互作用导致了压力和变形的耦合，这可以作为表面变形的驱动机制，在微流体、光学和软机器人等广泛应用中得到应用。这种配置的实现固有地发生在有限的域上，并且通常需要对板材进行一些预拉伸。在假定润滑弹性板具有强预拉伸和小变形的前提下，我们利用线性化的Reynolds方程和Föppl-von Kármán方程，导出了考虑弯曲和拉伸效应的有限域内的封闭解析解。我们给出了方形驱动区域的封闭解，并给出了预拉伸对变形动力学的影响。我们进一步提出了变形幅度和时间尺度对空间波数的依赖，以及在拉伸和弯曲主导政体之间的过渡。我们还演示了空间离散化力（代表实际驱动元素）对可实现的变形分辨率的影响。将问题扩展到轴对称域，我们研究了由雷诺方程和Föppl-von Kármán方程的非线性引起的影响，并呈现了变形行为，因为它与初始膜厚度相当，并依赖于诱导张力。这些结果为基于弹性流体力学的微流体软执行器的实现奠定了理论基础。
The interaction of a thin viscous film with an elastic sheet results in coupling of pressure and deformation, which can be utilized as an actuation mechanism for surface deformations in a wide range of applications, including microfluidics, optics and soft robotics. Implementation of such configurations inherently takes place over finite domains and often requires some pre-stretching of the sheet. Under the assumptions of strong pre-stretching and small deformations of the lubricated elastic sheet, we use the linearized Reynolds and Föppl–von Kármán equations to derive closed-form analytical solutions describing the deformation in a finite domain due to external forces, accounting for both bending and tension effects. We provide a closed-form solution for the case of a square-shaped actuation region and present the effect of pre-stretching on the dynamics of the deformation. We further present the dependence of the deformation magnitude and time scale on the spatial wavenumber, as well as the transition between stretching- and bending-dominant regimes. We also demonstrate the effect of spatial discretization of the forcing (representing practical actuation elements) on the achievable resolution of the deformation. Extending the problem to an axisymmetric domain, we investigate the effects arising from nonlinearity of the Reynolds and Föppl–von Kármán equations and present the deformation behaviour as it becomes comparable to the initial film thickness and dependent on the induced tension. These results set the theoretical foundation for implementation of microfluidic soft actuators based on elastohydrodynanmics.
影响因子：
56.9
作者：
Unger, MA;Chou, HP;Quake, SR
通讯作者：
Quake, SR
影响因子：
8.6
作者：
Pihler-Puzovic, D.;Illien, P.;Juel, A.
通讯作者：
Juel, A.