Characterization of a 10 W class electrospray array thruster.

A porous conical type electrospray array thruster consisting of 6102 individual emitters is operated at up to 13.3 W power. The design and manufacture of the thruster are described, including its porous glass emitter chip and metallized ceramic extractor chip. A precision mass balance mounted inside a bell jar is used to directly measure the thrust, specific impulse, and efficiency in negative polarity, from $42\pm 0.5\mu$ N, $1050\pm 26$ s, and $57\pm 1.9$ % at $-1000$ V and 0.38 W to $174\pm 0.5\mu$ N, $420\pm 2$ s, and $21\pm 0.3$ % at $-1300$ V and 1.7 W. Additional negative polarity experiments in a 2 meter vacuum facility demonstrate powers from order 1 $\mu$ W to over 10 W, spanning 7 orders of magnitude. Power and performance measurements were not repeated for positive mode operation, as this was found to induce arcing between the emitter and extractor electrodes at 1400 V and above. The drop in efficiency from $-1000$ V to $-1300$ V operation in the bell jar is discussed within the context of facility effects, and secondary charged particle flux to the thruster is identified as a likely contributor. Finally, the performance of the thruster is considered relative to scaling electrospray systems to higher power robustly.

Supplementary information: The online version contains supplementary material available at 10.1007/s44205-025-00114-4.