An experimental study was conducted to determine the heat removal ability of multiwall carbon nanotubes (MWNTs) grown in a silicon minichannel with water as the cooling medium. Two different devices based on different MWNT architectures - one fully covered with MWNTs and the other with 6 x 12 (rows, columns) of MWNT bundles were tested and compared to a device with no MWNTs. The performance was evaluated based on a constant heat flux applied to the silicon base versus the corresponding silicon base temperature. The experiments were performed at two different volumetric flow rates of 40 ml/min and 80 ml/min. The experimental results were also compared to computational modeling results. It was observed that the presence of MWNTs enhanced the heat removal from the silicon base. For the 6 x 12 MWNT bundles device, a silicon base heat flux that was 2.3 times the heat flux to the no MWNTs device can be applied, whereas for the fully covered MWNTs device 1.6 times the heat flux can be applied while still keeping the same silicon base temperature. (C) 2011 Elsevier Ltd. All rights reserved.