Vulcanized
rubber is widely used in a wide range of applications
because of its flexibility, durability, sealing properties, and high
degree of friction. However, this high degree of friction can also
become an issue, as it leads to the wearing and breakage of parts.
In this report, we investigated the effects of the vulcanized rubber
microstructures on friction force by using simple, anisotropic microstructures.
The line and space master microstructures were prepared from a photoresist,
and the structures were transferred to PDMS, PSt, and then Ni. After
surface modification of the Ni microstructures by TEOS, the vulcanized
rubber microstructures were fabricated by a simple hot press process
with the TEOS-coated Ni microstructure molds. The structural parameters
of the vulcanized rubber line and space microstructures were found
to be successfully varied by elongation, and the structural deformations
were also investigated by FEM simulations. Measurements of the frictional
force of the vulcanized rubber microstructures revealed the friction
coefficient was reduced by the surface microstructures and was affected
by the directions of the contact because of the microstructure anisotropy.
The reason for of these results can be explained by the changes in
the contact area and hysteresis friction. These results suggest that
the friction coefficients of vulcanized rubbers can be reduced by
the simple surface microstructures that are applicable to a wide range
of fields.