Tunable Dry Adhesion of Soft Hollow Pillars through Sidewall Buckling under Low Pressure
Tunable Dry Adhesion of Soft Hollow Pillars through Sidewall Buckling under Low Pressure
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DOI：
10.1002/adfm.202209905
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发表时间：
2022-11
影响因子：
19
通讯作者：
Guangchao Wan;Yanbing Tang;K. Turner;Teng Zhang;W. Shan
中科院分区：
文献类型：
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作者：
Guangchao Wan;Yanbing Tang;K. Turner;Teng Zhang;W. Shan
按需控制附着力对于许多制造和组装过程是必不可少的，例如微转移印刷。在各种策略中，气动控制的可切换粘接是高效和坚固的，但目前仍面临小型化和高能源成本的挑战。介绍了一种通过诱导软质空心柱(SHPS)的侧壁屈曲来实现低压可调粘着的新方法。结果表明，在较低的活化压力下(≈−10或≈20 kPa.)，这些SHPS的干附着力可以改变两个数量级以上(最高可达15 1倍)。足够大的负压会引发侧壁屈曲，而正压会导致侧壁鼓包，两者都会显著改变底部表面的应力分布，从而促进裂纹的萌生，减少粘附性。结果表明，微泵可以激活单个小泵来操纵各种不同曲率和表面纹理的轻质物体。这里还演示了SHPS阵列可以实现对对象阵列的选择性拾取和放置。这些演示展示了这些具有高度可调干附着力的SHPS的坚固性、简单性和多功能性。
Controlling adhesion on demand is essential for many manufacturing and assembly processes such as microtransfer printing. Among various strategies, pneumatics‐controlled switchable adhesion is efficient and robust but currently still suffers from challenges in miniaturization and high energy cost. In this paper, a novel way to achieve tunable adhesion using low pressure by inducing sidewall buckling in soft hollow pillars (SHPs) is introduced. It is shown that the dry adhesion of these SHPs can be changed by more than two orders of magnitude (up to 151×) using low activating pressure (≈−10 or ≈20 kPa). Large enough negative pressure triggers sidewall buckling while positive pressure induces sidewall bulging, both of which can significantly change stress distribution at the bottom surface to facilitate crack initiation and reduce adhesion therein. It is shown that a single SHP can be activated by a micropump to manipulate various lightweight objects with different curvatures and surface textures. Here, it is also demonstrated that an array of SHPs can realize selective pick‐and‐place of an array of objects. These demonstrations illustrate the robustness, simplicity, and versatility of these SHPs with highly tunable dry adhesion.