Investigation of Exothermic Behaviors of Energetic Particles in Microfluidics Channels

Abstract Energetic composites are highly suitable thermal energy source for microelectromechanical systems devices, especially fluidics devices. This study investigates the delivery and energy release of Al@CuO core‐shell thermite microparticles in a microchannel filled with NaCl solution. Their transportation and ignition are achieved using electrical microfluidic transport and plasma generated by electrical discharging at various voltage conditions. The microchannel featured a converging–diverging geometry optimized for non‐intrusive electrical discharging at its throat and jet formation at its exit. Numerical simulation is carried out to model the spatial electrical potential distributions. Experimental results confirmed the microparticles are able to be transported and collected at the throat at low voltage while Joule heating induced bubble formation and subsequent electrical breakdown occurred at 120 V. At a higher voltage of 500 V, electrical discharging happened ubiquitously in solution, resulting in the ignition of energetic particles, resulting in a high momentum butterfly‐shaped jet. The temperature profiles, achieved through high‐speed infrared imaging, show the originally symmetrical temperature distribution surrounding the throat is extended to a broader zone with high temperatures at its center. Finally, the combustion of Al@CuO in microchannel is confirmed by 488 nm emission footprint, which agreed with the high‐temperature hot spots during the exothermic process. Microstructural analysis also demonstrates the existence of combustion products.