The ability to control adhesion with a high tuning ratio and robust performance in a reversible manner is highly desirable for many engineering applications. Here, by embedding low-melting-point alloy (LMPA) blocks in a polymer matrix, we design a composite structure, whose surface adhesion can be actively switched between high and low when the LMPA is cooled to solid state or heated to liquid state. The proposed strategy does not need to modify the surface/interface directly yet can easily achieve an adhesion switching ratio about 100. As revealed by a contact mechanics model and finite element simulation, the adhesion tuning capability is enabled by rational regulation of the interface decohesion mode. More specifically, the interface will separate uniformly and exhibit high adhesion when the LMPA is solid; however, the interface will detach through crack-like propagation and exhibit much weaker adhesion when the LMPA is liquid. Based on this essential mechanism, we proceed to design a composite array structure, demonstrating that programmable inhomogeneous adhesion can be potentially achieved with pixel-by-pixel control capability.

许多工程应用非常需要以可逆方式以高调谐比和稳健性能控制粘附的能力。在这里，通过在聚合物基体中嵌入低熔点合金 (LMPA) 块，我们设计了一种复合结构，当 LMPA 冷却到固态或加热到液态时，其表面附着力可以在高低之间主动切换。所提出的策略不需要直接修改表面/界面，但可以轻松实现约 100 的粘附切换比。 正如接触力学模型和有限元模拟所揭示的，通过合理调节界面脱聚模式可以实现粘附调整能力. 更具体地说，当LMPA为固体时，界面将均匀分离并表现出高附着力；然而，当 LMPA 为液体时，界面将通过裂纹扩展而分离，并表现出更弱的粘附力。基于这一基本机制，我们继续设计复合阵列结构，证明可编程的非均匀粘附可以通过逐像素控制能力实现。