Soft lithography is used to fabricate substrates with surface topographies and structures at the nano- and micro-meter scale with high fidelity, repeatability and at low cost. Generally, it has been successfully used to transfer well-defined micro sized patterns from silicon or stainless-steel masters to surfaces of soft materials and biomaterials eg natural or synthetic polymers, allowing the replication of controlled microenvironments. The principle behind Soft Lithography: an elastomeric stamp or mold is the key element that transfers the pattern to the soft substrate and flexible organic molecules and materials are used.
Soft lithography is used to produce well defined micro and nano-sized patterns such as microcones, ripples, grooves etc from a master substrate to an elastomer mold (negative replica). Master substrates are usually very stiff and rigid, so the role of the elastomer is to be separate of the master and polymeric replica. Poly(dimethylsiloxane) (PDMS) is the most widely used elastomer mold because it has excellent properties, such as excellent flexibility, optical transparency, chemical resistance, durability, ease of release/peeling off, reversible deforming properties, and low cost.