Replica molding process

The concept of polymer-based 3D microstructure utilizes replica molding. Therefore, the key fabrication processes include 3D mold fabrication and pattern transfer. The material property is a very important factor when choosing the polymer and mold materials for special applications. For easy handling and accurate shape transfer, the mold requires smooth surface and relatively low thermal expansion coefficient since the curing of the polymer often involves heat. Nowadays, several polymer materials such as PDMS, PMMA, and SU-8 are popular choices for microfluidic applications. 

Soft Lithography Soft lithography represents a non-photolithographic strategy based on self-assembly and replica molding for carrying out micro and nanofabrication [4]. It has been mostly developed in recent years. It is a favorable process for researchers to build nanometer-scale structures. It includes the following techniques ... 

Soft molding uses the elastomeric PDMS stamp instead of hard molds to obtain polymer replicas via molding processes. Using an elastomeric, flexible mold makes... 

By using REM, the precious hard master mold is only exposed to PDMS, allowing the master to be used numerous times to produce any number of replica molds, and is therefore not involved in the imprinting process, thus extending the lifetime available to the hard master mold. 

The printing process can be separated into two parts fabrication of the stamp and use of this stamp to pattern features defined by the relief on its surface. These two processes are typically quite different, although it is possible in some cases to use patterns generated by a stamp to produce a replica of that stamp. The structure from which the stamp is derived, which is known as the master , can be fabricated with any technique that is capable of producing well-defined patterns of surface relief. This master can then be used directly as the stamp, or it can be used to produce stamps via molding or printing procedures. 

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