Low Concentration Response Hydrogen Sensors Based on Wheatstone Bridge.

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Hydrogen sensors are crucial for safety and industrial monitoring.
• Micro-electro-mechanical system (MEMS) technology enables miniaturization and integration of sensor components.

Purpose of the Study:

• To design and fabricate a PdNi film hydrogen sensor using MEMS technology.
• To investigate the hydrogen sensing properties of the fabricated sensor.
• To evaluate sensor performance at various temperatures and hydrogen concentrations.

Main Methods:

• Fabrication of PdNi and silicon nitride films using magnetron sputtering.
• Characterization of film morphology and microstructure using X-ray diffraction (XRD).
• Integration of four PdNi resistors in a Wheatstone bridge configuration for sensing and reference.
• Conversion of resistance output to voltage for data acquisition.

Main Results:

• The PdNi film hydrogen sensor exhibited distinct responses across a range of hydrogen concentrations (10 ppm to 0.4%).
• High repeatability was observed during cycle testing at 0.4% H₂ concentration.
• A clear and collectable output voltage of 600 μV was detected at 10 ppm hydrogen.

Conclusions:

• The developed MEMS-based PdNi film hydrogen sensor demonstrates effective hydrogen detection capabilities.
• The sensor shows promise for applications requiring sensitive and reliable hydrogen monitoring.
• The Wheatstone bridge configuration enhances sensor performance and data acquisition.