The soft lithographic fabrication of high-aspect-ratio polydimethylsiloxane (PDMS) microstructures is quite challenging because of the strong interfacial adhesion between them and masters during demolding. This paper presents a simple method for fabricating high-aspect-ratio PDMS microstructures by reducing the interfacial adhesion through the cooling process. The effect of cooling process on the topography, elastic property, and adhesion property of Sylgard 184 PDMS is studied. It is found that wrinkles are formed on the surface of PDMS and that the Young’s modulus of PDMS is increased by the air cooling process. Consequently, the air-cooled PDMS has lower adhesion than the traditional oven-cooled PDMS. This result could be explained by the adhesion parameter theory: both the high amplitude of the wrinkles formed on the surface of PDMS and the high Young’s modulus of PDMS increase separation forces and reduce adhesive forces in the interface. Application of this method is demonstrated by fabricating PDMS microchannels from a silicon master which has microstructures with different aspect ratios. Compared with PDMS microchannels obtained by the oven cooling process, PDMS microchannels with a depth of 200 μm and an aspect ratio of 10 are successfully fabricated by the air cooling process.

高纵横比聚二甲基硅氧烷 (PDMS) 微结构的软光刻制造非常具有挑战性，因为它们在脱模过程中与母版之间具有很强的界面附着力。本文提出了一种通过冷却过程减少界面粘附来制造高纵横比 PDMS 微结构的简单方法。研究了冷却过程对 Sylgard 184 PDMS 的形貌、弹性和粘附性能的影响。发现在PDMS表面形成皱纹，并且通过空气冷却过程增加了PDMS的杨氏模量。因此，风冷 PDMS 的附着力低于传统的烘箱冷却 PDMS。这个结果可以用粘附参数理论来解释：PDMS 表面形成的皱纹的高幅度和 PDMS 的高杨氏模量都增加了分离力并降低了界面的粘附力。该方法的应用通过从具有不同纵横比的微结构的硅母模制造 PDMS 微通道来证明。与烘箱冷却工艺获得的PDMS微通道相比，深度为200的PDMS微通道通过空气冷却工艺成功制造了μ m 和 10 的纵横比。