<p>Many micro-devices, such as chemical reactors, biomedical devices, microelectronic circuits, and micro-electromechanical systems, generate heat during use, leading to performance degradation. Thus, these small electronic devices need cooling cycles to operate effectively. Various solutions have been developed to address significant heat dissipation, including impact jet cooling, spray cooling, micro-heat, thermoelectric coolers, and micro-channel heat sinks. This work aims to address the research gap in micro-channel heat sink performance by investigating the effects of fins geometry, such as shapes and twists, on its overall thermal performance. Specifically, it examines how different fin shapes with twists impact the overall thermal performance factor. By incorporating inward-projected fins into the micro-channels and comparing the performance of twisted versus untwisted fins, this research seeks to enhance the global performance of micro-channel heat sinks used for cooling electronic chips and appliances. For this purpose, computational fluid dynamics analysis was done to analyse the effect of these geometrical changes on the thermal and hydraulic performance of the fin under laminar conditions. Our findings demonstrate that twisted fins significantly outperform the untwisted fins in terms of heat transfer but at the cost of higher pressure drop. Among all the geometries studied, twisted rectangular fins have been found to offer the best performance, up to 57.88&#xa0;°C reduction in heat sink bulk temperature compared to circular channels without any fins. The results indicate that geometry optimisation holds significant potential for enhancing the performance of micro-channels.</p>