Friction in micromanufacturing

Friction plays a vital role in several micromanufacturing processes. Since the eighteenth century, the phenomenon of friction has been widely investigated, but it is still one of the least understood subjects. In this article, a review of studies on friction in micromanufacturing is presented with a background of existing knowledge at the macro level. While there is a general recognition that force of friction is several times higher in micromanufacturing than that in conventional manufacturing, there is a dearth of robust and reliable models, especially suited for micromanufacturing. At present, a pocket model can be considered as the only friction model for micromanufacturing, which demonstrates how friction increases considerably with diminishing size under lubricated conditions. However, this model does not capture the physics of friction under dry conditions, which may be heavily dependent on the grain size as well. There are several contradictory results in the literature, particularly with regard to the roles of surface roughness and temperature. Thus, there is a need to carry out an in-depth investigation on the tribology of micromanufacturing processes.