Microfluidic Microreactor Device With Integrated Heaters for Temperature Assisted Synthesis of Gold Nanoparticles and Alkene

Thermal synthesis is an essential process in most chemical formulations. While several well-established methods exist for synthesizing materials in large quantities, synthesizing materials on a small scale is challenging and costly. This work delves into the design and functionality of microfluidic-based thermal synthesis microreactors, which are highly customizable and cost-effective. Instead of conventional electrothermal heaters, Laser-Induced Graphene (LIG) heaters are leveraged over traditional electrothermal heaters due to their cost-effectiveness, simplified fabrication process, and high level of customization. The parameters for developing these LIG heaters were optimized by tuning the speed and power of the CO₂ laser to obtain both the desired electrical conductivity and mechanical strength. The developed heaters were integrated with microfluidic devices fabricated using the soft-lithography technique. The functionality of these devices was demonstrated by performing gold nanoparticles (inorganic) and alkene (organic) synthesis. The synthesized gold nanoparticles (AuNPs) and alkene solution were analyzed using UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and Nuclear Magnetic Resonance (NMR) techniques to evaluate the quality of the end products. The functionality of synthesized solutions can be utilized as catalyst in electrochemical applications and as precursors in downstream chemical syntheses.