Simulation and Analysis of Metal Microfluidic Heatsinks

Microfluidic heatsinks are usually fabricated in silicon substrates using micromachining methods. Fabrication of microfluidic heatsinks in metals is captivating due to the potential of higher heat conductance of many metals compared to silicon. In this work, metallic microfluidic structures fabricated of copper, silicon, and nickel are simulated and analyzed using the FEM method. The parametric dependence of the overall thermal resistance on the heatsink material, fluid velocity, and channel geometry is examined. Their performance is compared based on the shape and size of the microchannels, their separating distance from each other, and the flow rate. Simulations were done using FEMLAB v.3.2 (Comsol Multyphysics). The length of the microchannels considered is 1cm. Their cross section is rectangular. Simulated heatsinks are covered with 50 μm of the same material as the body and the total area of the heat sink is 1cm × 1cm. Water is used as the coolant with an input temperature of 300 K. These simulations show that most of the thermal resistance in the heatsink occurs in the fluid region. For the constant and uniform input heating power of 100 W/cm² the performance of the structure is studied at steady state with the fluid velocity varied from 1 to 14m/s. Finally, experimental fabrication of an electroplated copper micro-channel system with rectangular channels is shown.