Microchannel heat sinks (MCHSs) are promising thermal solutions in miniaturized or compact devices. Light-weight aspect has been given huge emphasis in recent years. Metal-based materials are commonly used to fab-ricate MCHSs due to their high thermal conductivity. Consequently, MCHSs are heavy due to the high density of these materials albeit the small footprint of MCHSs. Polymer-based materials are interesting altatives. Despite their poor thermal conductivity, lightweight feature attracts the interest of researchers. Heat transfer is a conju-gate process of heat conduction and heat convection. Poor heat conductions aspect may be compensated through enhancement of heat convection aspects. Although polymer-based materials have been used in microscale heat transfer studies, their focus was not on their feasibility. The present study aims to evaluate the feasibility of polymer-based MCHSs as thermal solutions. The effect of thermal conductivity of fabrication materials, including polymer-based PDMS, PTFE, PDMS/MWCNT, and metal-based aluminum, on the thermal performance of MCHSs was investigated and compared at various inlet flow rate,fluid thermal conductivity, and microchannel ratio at different constant heat fluxes using three-dimensional CFD approach. Results showed that the thermal perfor-mance of MCHSs was greatly affected by the heat conduction aspect in which poor heat conduction limited the thermal performance improvement due to enhanced heat convection aspects. This suggests polymer-based materials have the potential for heat transfer applications through thermal conductivity enhancement. This was confirmed in the further analysis using a recently proposed high thermal conductivity polymer-based graph-ite/epoxy MCHS and a hybrid-based PDMS/aluminum MCHS.