At present

channels made of copper

aluminum or stainless steel are widely used for the heat transfer enhancement research

but the fabrication precision and size of these traditional channels are usually limited.In this paper

silicon-based microchannels with square internal ribs were made by the MEMS method

and their flow and heat transfer characteristics were experimentally investigated for the first time.It was shown that the flow and heat transfer characteristics were affected apparently by rib height and the distance between two neighboring ribs.When compared with the smooth silicon microchannels without internal ribs

both the friction factors and Nusselt numbers of the silicon microchannels with internal ribs increased

and the heat transfer enhancement performance of the silicon-based microchannels with internal ribs was mainly dependant on rib height and rib distance.The entrance effect on the flow and heat transfer in the silicon microchannels was obvious.