Multi-colour micro-contact printing based on microfluidic network inking

We report on a simple method of multi-colour micro-contact printing (MC mu CP) that can be applied for monolayer molecular patterning of different types of molecules at the same time. Soft lithography has been used to fabricate specially designed microfluidic channel structures (top layer) and stamps for micro-contact printing (bottom layer). We have taken advantage of the spatial resolution of microfluidics networks and their numerous channels to bring into contact the solutions of molecules and the micro-contact printing stamp on a very precise and defined surface. Thus, we can vary the type of molecules deposited as well as the shape of the deposition by varying the number and design of microfluidic channels. This particular use of the microfluidic networks has been enabled by tightly but reversibly sealing the microfluidic networks on the stamp by using succion around the channels to prevent any leakage. After the molecules deposition and the peeling off of microfluidic channels, the micro-contact printing stamp can be used for micro-contact printing in a traditional manner. Our results show that the established MC mu CP method enables precise protein deposition numerous in types, shapes and proportions, thereby allowing one to develop a variety of bio-applications. (c) 2006 Elsevier B.V. All rights reserved.