Ionization Potential Tunable Pyroelectric Ambient Pressure Multi-Gas Detection Platform

In this paper, we demonstrate a novel, ionization potential tunable gas detection platform. Tuning the ionization potential allows gradual ionization of different gases, therefore potentially enabling gas identification. It opens up significant opportunity for developing miniature sensors for applications in air quality, environmental monitoring, toxic gas detection, and consumer-related products. The tunable ionization potential is produced using lithium niobate pyroelectric crystal by controlling its heating temperature rate. The ionization potential generated from pyroelectrically emitted electrons can be tuned with the heating rate and gap between the detection electrode and pyroelectrically charged surface. Lithium niobate pyroelectric ionization source was established by integrating a Peltier-based heating system and fabricated ionization detection electrode. Thermal distribution on the crystal surface is studied using Multiphysics COMSOL simulation and compared with experimentally measured values. Pyroelectrically generated surface potential is measured for different temperature rates using the electrostatic cantilever approach. Ionization of vapors of acetone, isopropyl alcohol, ethanol, and ambient air was carried out at different temperature rates and different electrode gaps to demonstrate the ionization potential tunability. Obtained results showed a clear distinction between the ionization of volatile organic compounds (VOCs) and ambient air.