Autonomous fluidic components are critical to the advancement of integrated micro/nanofluidic circuitry for lab-on-a-chip applications, such as point-of-care (POC) molecular diagnostics and on-site chemical detection. Previously, a wide range of self-regulating microfluidic components, such as fluidic diodes, have been developed; however, achieving effective functionality at ultra-low Reynolds number (e.g., Re < 0.05) has remained a significant challenge. To overcome this issue, here we introduce single-layer microfluidic "domino" diodes, which utilize free-standing rotational microstructuresconstructed in situ via optofluidic lithography -in order to passively regulate the fluidic resistance based on the flow polarity, thereby enabling flow rectification under ultra-low Re conditions. COMSOL simulation results revealed a theoretical Diodicity (Di) of 31 for a singular domino diode component. Experimental results (for systems with four microstructures) revealed Di's ranging from 13.0±1.9 to 25.4±1.9 corresponding to 0.025 < Re < 0.030 and 0.010 < Re < 0.015 flow, respectively, which represent the largest Di's reported for Re < 0.05 fluid flow.

The effect of thermal radiation and conduction on the cold-wall flame-quenching distance in the combustion of condensed fuels is studied by use of a simple physical model under steady-state, no-flow conditions. The singular perturbation technique is employed for the flame layer analysis, and the quenching layer is assumed to be optically thin. The quenching distance is obtained as a function of various therrnophysical and radiative parameters such as the conduction-radiation ratio, optical thickness and heat generation intensity by chemical reactions. A new dimensionless group, the modified Damkohler number, which characterizes the relative strength of heat generation to radiation transport, emerges from the analysis. Also, the present analysis suggests a potential experimental scheme for measuring the extinction temperature in the specified combustion configurations.