Development of a Tuneable NDIR Optical Electronic Nose

Area of Science:

• Analytical Chemistry
• Sensor Technology
• Spectroscopy

Background:

• Electronic nose (E-nose) technology is crucial for chemical sample analysis in food safety, environmental monitoring, and medical diagnostics.
• Current E-noses often use metal oxide (MOX) or conducting polymer (CP) sensors, which face challenges like sensor drift, poor repeatability, and environmental interference.
• Optical gas sensors present a potential solution to overcome the limitations of existing E-nose technologies.

Purpose of the Study:

• To develop and demonstrate an optical non-dispersive infrared (NDIR) E-nose.
• To evaluate the performance of the NDIR E-nose in detecting and discriminating chemical samples.

Main Methods:

• The study developed an NDIR E-nose equipped with an array of four tuneable detectors capable of scanning wavelengths from 3.1 to 10.5 μm.
• Gas rig tests were conducted using carbon dioxide (CO2) and methane (CH4) at various concentrations.
• The device's ability to discriminate between chemical standards and complex mixtures was assessed.

Main Results:

• The optical gas sensor responses exhibited a linear to polynomial relationship with different concentrations of CO2 and CH4.
• The NDIR E-nose demonstrated good discrimination capabilities between different sample groups.
• The developed optical E-nose proved functional and effective in gas analysis.

Conclusions:

• Optical E-nose technology, specifically the NDIR approach, shows significant potential for overcoming the limitations of MOX and CP sensors.
• This technology offers a portable and low-cost solution for diverse E-nose applications.
• The developed NDIR E-nose is a viable tool for accurate chemical sensing and analysis.