Correlation-function-based microstructure design of alloy-polymer composites for dynamic dry adhesion tuning in soft gripping
Correlation-function-based microstructure design of alloy-polymer composites for dynamic dry adhesion tuning in soft gripping
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DOI：
10.1063/5.0082515
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发表时间：
2022-03
影响因子：
3.2
通讯作者：
Yaopengxiao Xu;Pei-En Chen;Hechao Li;Wenxiang Xu;Yi Ren;W. Shan;Yang Jiao
中科院分区：
文献类型：
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作者：
Yaopengxiao Xu;Pei-En Chen;Hechao Li;Wenxiang Xu;Yi Ren;W. Shan;Yang Jiao
可调干粘附是柔顺操作的关键机制。夹持力可以通过可逆地改变物理性质（例如，通过外部刺激改变复合材料的刚度）。最大夹持力Fmax及其可调性取决于夹持界面上的应力分布及其断裂动力学（在分离期间）等因素，而这些因素又由复合材料微观结构决定。在这里，我们提出了一个计算框架的建模和设计的一类二元智能复合材料包含一个多孔的低熔点合金（LMPA）相和聚合物相，以实现理想的动态可调干粘附。我们采用空间相关函数来量化，建模，并表示复杂的双连续的复合材料的微观结构，从现实的虚拟三维复合材料的微观结构，可以使用随机优化产生广泛的频谱。最近开发的体积补偿格子粒子方法，然后采用动态界面断裂过程建模，其中的夹具是从对象分离，计算Fmax为不同的复合材料微观结构。我们专注于界面缺陷的调整机制，使复合材料的干粘附调整，并发现，在这里研究的一个最佳的微观结构，Fmax之前和之后的LMPA相的热膨胀的十倍动态调谐可以实现。计算结果可为LMPA-聚合物复合材料的实验制备提供有价值的指导。
Tunable dry adhesion is a crucial mechanism in compliant manipulation. The gripping force can be controlled by reversibly varying the physical properties (e.g., stiffness) of the composite via external stimuli. The maximal gripping force Fmax and its tunability depend on, among other factors, the stress distribution on the gripping interface and its fracture dynamics (during detaching), which in turn are determined by the composite microstructure. Here, we present a computational framework for the modeling and design of a class of binary smart composites containing a porous low-melting-point alloy (LMPA) phase and a polymer phase, in order to achieve desirable dynamically tunable dry adhesion. We employ spatial correlation functions to quantify, model, and represent the complex bi-continuous microstructure of the composites, from which a wide spectrum of realistic virtual 3D composite microstructures can be generated using stochastic optimization. A recently developed volume-compensated lattice-particle method is then employed to model the dynamic interfacial fracture process, where the gripper is detached from the object, to compute Fmax for different composite microstructures. We focus on the interface defect tuning mechanism for dry adhesion tuning enabled by the composite, and find that for an optimal microstructure among the ones studied here, a tenfold dynamic tuning of Fmax before and after the thermal expansion of the LMPA phase can be achieved. Our computational results can provide valuable guidance for experimental fabrication of the LMPA–polymer composites.