Feng Xue, Meitl Matthew A, Bowen Audrey M, Huang Yonggang, Nuzzo Ralph G, Rogers John A
Department of Engineering Mechanics, Tsinghua University, Beijing, China.
Langmuir. 2007 Dec 4;23(25):12555-60. doi: 10.1021/la701555n. Epub 2007 Nov 9.
Transfer printing by kinetically switchable adhesion to an elastomeric stamp shows promise as a powerful micromanufacturing method to pickup microstructures and microdevices from the donor substrate and to print them to the receiving substrate. This can be viewed as the competing fracture of two interfaces. This paper examines the mechanics of competing fracture in a model transfer printing system composed of three laminates: an elastic substrate, an elastic thin film, and a viscoelastic member (stamp). As the system is peeled apart, either the interface between the substrate and thin film fails or the interface between the thin film and the stamp fails. The speed-dependent nature of the film/stamp interface leads to the prediction of a critical separation velocity above which separation occurs between the film and the substrate (i.e., pickup) and below which separation occurs between the film and the stamp (i.e., printing). Experiments verify this prediction using films of gold adhered to glass, and the theoretical treatment extends to consider the competing fracture as it applies to discrete micro-objects. Temperature plays an important role in kinetically controlled transfer printing with its influences, making it advantageous to pickup printable objects at the reduced temperatures and to print them at the elevated ones.
通过对弹性印章进行动力学可切换粘附的转移印刷，有望成为一种强大的微制造方法，用于从供体基板拾取微结构和微器件，并将它们印刷到接收基板上。这可以看作是两个界面的竞争断裂。本文研究了由弹性基板、弹性薄膜和粘弹性部件（印章）组成的模型转移印刷系统中的竞争断裂力学。当系统被剥离时，要么基板与薄膜之间的界面失效，要么薄膜与印章之间的界面失效。薄膜/印章界面的速度依赖性导致预测出一个临界分离速度，高于该速度时薄膜与基板之间发生分离（即拾取），低于该速度时薄膜与印章之间发生分离（即印刷）。实验使用附着在玻璃上的金薄膜验证了这一预测，并且理论处理扩展到考虑竞争断裂在离散微物体上的应用。温度在动力学控制的转移印刷中起着重要作用，它具有影响，使得在降低的温度下拾取可印刷物体并在升高的温度下进行印刷是有利的。
