The main purpose of this research work is the demonstration that soft-lithography, very often called Micro-Contact Printing (μCP) is an efficient patterning technique for arranging biomolecules on a surface in the perspective of biochip applications. For DNA Micro-arrays applications, we demonstrate that μCP is a competitive method compared to the conventional spotting technology, commonly used today. The cost of the technology is much lower, the surface density of the chip is drastically increased and the quality and definition of the biopatterns are greatly improved. A systematic study of the inking mechanisms of the elastomeric stamps is provided together with the study and comprehension of transfer mechanisms of molecules from the surface of the stamp to the substrate. The crucial role played by the free fragments of polymers not cross-linked during the polymerisation of the stamp is highlighted. In a second section we investigate the possibility of using μCP for generating single biomolecule biochips. We show how this printing technique can be optimized for reaching sub-micrometric scale down to 50 nanometers features. A technological process involving soft-lithography is proposed: combing long DNA molecules on spatially organized and registered positions for genetic applications.