A Parametric Study Optimizing the Fabrication Parameters of Chemically Oxidized Porous Silicon for Microthruster Applications

Over the past decade, extensive research has investigated the reactive properties of porous silicon (PSi) in combination with chemical oxidizers, revealing its potential for precise and reproducible thrust for advanced microthruster applications. In this work, we optimize the energetic output through a parametric study focusing on PSi formation parameters and chemical oxidizer application parameters. The parameters applied in the electrochemical anodic oxidation process used to make PSi define the pore morphology of the substrate. Electrolyte concentration, current density, and etch time are investigated parametrically to determine optimal fabrication parameters yielding morphologies with maximum energetic output. Chemical oxidizer uptake also has a significant effect on the energetic output of explosive PSi. Oxidizer concentration, application quantity, and post application drying process are investigated to determine parameters for optimal results. Groundwork has been completed proving calorimetric techniques to be viable for accurate and reproducible determination of energetic output of explosive PSi samples. Through calorimetry, this study identifies optimal formation parameters of chemically oxidized PSi to maximize energetic output thereby advancing the material’s potential for solid propellant microthruster applications. Theories will be discussed for effects of parametric variation on energetic output.