Characterization of Energetic Porous Silicon for a Microelectromechanical System (MEMS)-Based Solid Propellant Microthruster.

摘要

Silicon can be converted into porous silicon (PS) through a galvanic etch process and then rendered energetic when infused with any one of a number of oxidizers. Energetic PS can provide variable energy release to generate thrust and the displacement of small-scale devices such as microthrusters and micro-satellites. In this report, we investigate the etch process and its repeatability for pore formation during etches. We found that using a fresh etch bath reduces variability in pore characteristics. In addition, we examine the thrust output of a combustion reaction of PS activated with sodium perchlorate. Experimental testing showed that the forces ranged from tens to hundreds of millinewtons, depending on the silicon wafer resistivity and pore morphology, which is controlled by the etch parameters.