Swelling-induced patterning in soft microchannels
Swelling-induced patterning in soft microchannels
复制标题
软微通道中膨胀引起的图案化
作者：
Li H
我们研究了充气对弹性薄膜膨胀引起的起皱的影响，该装置通常用于在芯片实验室应用中创建微通道。通过结合实验和相关的数值模拟，我们证明了膨胀膜的面外变形和由此产生的各向异性应力会导致膨胀过程中出现两种明显的不稳定性。膜首先形成小幅度的皱纹，以保持跨通道的对称性。它们的波长取决于压力，其设定过程类似于加压、单轴压缩圆柱壳的轴对称屈曲。随着膨胀的增加，膜经历二次不稳定性，在此期间皱纹变粗成大幅度的褶皱，其形态可以通过预膨胀的程度来控制。我们阐明了造成这种行为的基本机制，并解释了如何将膨胀用作微通道制造中的控制机制。
We study the effect of inflation on the swelling-induced wrinkling of thin elastic membranes in a set-up that is commonly used to create microchannels in lab-on-chip applications. Using a combination of experiments and associated numerical simulations, we demonstrate that the out-of-plane deformation of the inflated membrane and the resulting anisotropic stress lead to two distinct instabilities as the swelling progresses. The membrane first develops small-amplitude wrinkles that retain the cross-channel symmetry. Their wavelength depends on the pressure and is set in a process similar to the axisymmetric buckling of pressurised, uni-axially compressed cylindrical shells. As swelling increases, the membrane undergoes a secondary instability during which the wrinkles coarsen into large-amplitude folds whose morphology can be controlled by the degree of pre-inflation. We elucidate the fundamental mechanisms responsible for this behaviour and explain how inflation can be used as a control mechanism in the manufacture of microchannels.