3.1. Classification of Alternative Molding Materials

The objective of this section is to specify the wide range of molding materials for micro replication processes. In macroscopic molding, polymers are an established molding material. The advantage of polymers is the large bandwidth of different properties that allows one to find a suitable polymer for most applications. The great advantage is, further, the moderate temperature range and, if thermoplastic polymers are used, the reversible switch between the solid and viscous aggregate states. The knowledge of material behavior is essential for an analytic view on every replication process. Nevertheless, of the dissemination of polymer materials in the replication processes, alternative materials are also suitable for molding. These materials close a gap because these materials show properties that cannot be achieved by polymer materials. In this section some alternative molding materials and their relevance in micro replication processes are presented.

Independent of the molding material, here are the basic requirements that have to be fulfilled.

• The material has to be set into an aggregate state, where molding is possible (e.g., by heat or by chemicals).
• The viscosity of the melt should be in a range that allows molding with established technologies.
• After molding the melt has to be cured (e.g., by cooling, UV radiation, or chemical reactions).
• Reversible switching between the solid state and the melt is desired.
• Fillers or additional components of the material have to be significantly smaller than the size of the micro- or nanocavities.