The interface between two surfaces patterned with complementary shapes such as arrays of ridge–channel structures or pillars accommodates relative misorientation and lattice mismatch by spontaneous production of dislocation arrays. Here, we show that the relative sliding of such an interface is accomplished by dislocation glide on the interfacial plane. An exception is the singular case where the lattices are perfectly matched across the sample dimension, in which case sliding is accompanied by motion of edge-nucleated defects. These are meso-scale analogues of molecular sliding friction mechanisms between crystalline interfaces. The dislocations, in addition to the long-range elastic energy associated with their Burgers vectors, also cause significant out-of-plane dilation, which props open the interface locally. For this reason, the sliding friction is strongly pressure dependent; it also depends on the relative orientation of the patterns. Sliding friction can be strongly enhanced compared with a control, showing that shape-complementary interfaces can be engineered for strongly enhanced pressure- and orientation-dependent frictional properties in soft solids.

具有互补形状图案的两个表面之间的界面，例如脊 - 通道结构或柱的阵列，通过位错阵列的自发产生来适应相对错误取向和晶格失配。在这里，我们表明这种界面的相对滑动是通过界面平面上的位错滑动来完成的。一个例外是晶格在样品维度上完全匹配的奇异情况，在这种情况下，滑动伴随着边缘成核缺陷的运动。这些是晶体界面之间分子滑动摩擦机制的中尺度类似物。除了与 Burgers 矢量相关的长程弹性能量外，位错还会导致显着的面外膨胀，从而局部打开界面。为此原因，滑动摩擦强烈依赖于压力；它还取决于图案的相对方向。与对照相比，滑动摩擦可以大大增强，这表明形状互补的界面可以设计用于在软固体中强烈增强与压力和方向相关的摩擦特性。