Microcontact printing (ÁCP) is a soft lithography technique used for functionalizing a
surface by micropatterning. This technique is particularly attractive for biological applications as it offers the ability to pattern
substrates with complex molecules relevant to biology. For example, one can pattern a substrate with "cell-friendly" proteins to promote
the adhesion of cells.
Poly(dimethyl siloxane) (PDMS) is the most commonly used polymer for fabrication of the elastomeric stamp (commercial product: Sylgard 184 from Dow Corning). Typically, PDMS is casted from a reusable silicon master
obtained by deep
reactive ion etching. The elastomeric stamp is "inked" with a thin layer of proteins that is transferred to the bio-MEMS device
by μCP. Conformal printing is the key for successful μCP.
In our laboratory, we have developed a mechanical system for alignment of the elastomeric stamp with the bio-MEMS device.
With a resolution of a few micrometers, this system is appropriate for the micropatterning of protein layers having feature sizes of several tens of micrometers. The setup enables the
application of a well-controlled even pressure during the ÁCP process.