Integrated hybrid MEMS hydrogen sensor with high sensitivity and high dynamic range

Abstract

This paper discusses an integrated hybrid MEMS hydrogen sensor that detects hydrogen in the range from 5 ppm to 100 vol%. The sensor is a single chip comprising both capacitive and thermal conductivity hydrogen sensors that can be fabricated simultaneously using the same process flow. The capacitive sensor detected hydrogen at concentrations as low as 5 ppm without a heater. The thermal conductivity sensor measured high hydrogen concentrations and had a low power consumption of several tens of milliwatts. The integrated hybrid MEMS hydrogen sensor showed a high gas selectivity.