Low temperature performance of miniature capacitive pressure sensor with submicron gap

Recent development of micromachining techniques enables us to make tiny sensors, which are tempting for use in low temperature studies. We tested a miniature capacitive pressure sensor which was designed specially for a commercial sphygmomanometer, and report the low temperature performance. This sensor can distinguish a change of 0.05 Pa in the pressure of helium vapor estimated from a long term stability at 4.0 K. This type of miniature pressure sensor should be useful as a research tool at cryogenic temperatures.