Rational Design of 3D-Printed Microfluidic Chips for One-Step Production of Silver Nanofluids in Thermal Management of Power Electronic Chips

One-step continuous flow synthesis of nanofluids with superior heat transfer performance using microfluidic chips is an effective way to enhance flow-boiling heat transfer and address the thermal challenges of advanced electronic chips. However, the intricacy of conventional microfluidic chip fabrication techniques frequently results in assembly defects, flow channel seepage, and inhomogeneous mixing during the nanofluid synthesis process. In addition, the specific mechanisms of nanofluids as heat transfer media in enhancing the thermal management of electronic chips, particularly their impact on the dynamic behavior of bubbles during flow-boiling heat transfer, still require more in-depth studies. This study developed a three-dimensional helical microfluidic chip that exhibited excellent mixing performance under various operating conditions and achieved high-throughput continuous synthesis of silver nanofluids through combined simulation and experimental validation. The synthesized silver nanoparticles exhibited excellent colloidal stability (>60 days) and uniform nanoparticle size (<30 nm), and the size of silver nanoparticles could be controlled by adjusting the liquid flow rates of the inlets. The effects of nanofluid concentration and flow rate on flow-boiling heat transfer were investigated systematically. The results demonstrated that silver nanofluids showed significant enhancements, with the 0.01 wt % achieving a 65.66% increase in critical heat flux (CHF) and a 49.31% increase in heat transfer coefficient (HTC) at a flow rate of 160 mL/min. Additionally, visualization of the bubble's growth cycles showed that silver nanofluids could effectively shorten the bubble's lifetime, reduce the bubble's size, and increase the number of nucleation sites. These findings provided a method for integrating microfluidic chips with electronic chip research through high-throughput synthesis of nanofluids.