Shaping two-dimensional (2D) crystals with well-defined edges along specific directions remains technically challenging due to the intrinsic lattice discreteness and anisotropy in their fracture toughness. The patterns of crystal cleavage are determined by the fracture resistance and loading conditions, and usually display kinking features. We show that the fracture of single-crystalline 2D films (MoS₂, MoTe₂, graphene) can be controlled by mechanically-induced wrinkles, and the distortion of their profiles can visualize the distorted local strain state near the crack tip. In thin samples with stretch-induced wrinkles, the elastic driving force with effective anisotropy steers crack propagation, resulting in straight edges following the corrugation profile. In contrast, thick samples remain flat under stretch for their elevated bending resistance, and the cracks advance with sawtooth patterns following the zigzag motif. The experimental findings are explained by wrinkling-induced elastic anisotropy, which dominates over fracture anisotropy. The control of fracture in 2D crystals can be applied to fabricate micro- and nanostructures for their applications in electromechanical and optoelectronic devices.

由于固有的晶格离散性和断裂韧性的各向异性，沿特定方向塑造具有明确边缘的二维 (2D) 晶体在技术上仍然具有挑战性。晶体解理的模式由抗断裂性和加载条件决定，通常显示扭结特征。我们表明，单晶 2D 薄膜（MoS ₂、MoTe ₂，石墨烯）可以通过机械引起的皱纹来控制，并且它们的轮廓的变形可以可视化裂纹尖端附近扭曲的局部应变状态。在具有拉伸引起的皱纹的薄样品中，具有有效各向异性的弹性驱动力控制裂纹扩展，导致沿波纹轮廓的直边。相比之下，厚样品在拉伸下保持平坦，因为它们具有更高的抗弯曲性，并且裂纹沿着锯齿形图案以锯齿图案前进。实验结果可以用起皱引起的弹性各向异性来解释，它比断裂各向异性占主导地位。二维晶体的断裂控制可用于制造微结构和纳米结构，以用于机电和光电设备。