This disclosure relates to a method for making a polymeric article mold, a
method for making a polymeric article with that mold, and improved
surface topography features for a polymeric article. A prototype article
is formed and then coated with a thin conductive layer. The coated
prototype article is then electroformed until nickel plated to a
sufficient depth to define a nickel plating tool. After the prototype
article has been removed from the mold face of the nickel tool, the tool
can be used as a mold for forming finished polymeric articles which
replicate the original prototype article. The use of fine topography
features such as a dense upstanding stem array on the surface of the
prototype article facilitates accurate and complete electroforming by
increased surface area presentation. The disclosure also presents
improvements to microreplicated surface structures such as stem arrays.
The improvements include the formation on a stem array having separate
zones of stems of differing heights, and the formation of directional
microreplicated features (e.g., stems) which are oriented and shaped to
promote or restrict frictional interaction in one or more particular
directions.