Enhanced Sensing Characteristics in MEMS-based Formaldehyde Gas Sensor

TL;DR

This paper presents a novel self-heating NiO-based MEMS formaldehyde gas sensor with enhanced sensitivity and detection limits, suitable for industrial and health safety applications.

Contribution

Developed a new fabrication process for a self-heating NiO gas sensor with improved sensitivity through co-sputtering techniques.

Findings

Increased sensor sensitivity due to NiO/Al2O3 co-sputtering

Enhanced detection limit for formaldehyde

Suitable for industrial and health safety monitoring

Abstract

This study has successfully demonstrated a novel self-heating formaldehyde gas sensor based on a thin film of NiO sensing layer. A new fabrication process has been developed in which the Pt micro heater and electrodes are deposited directly on the substrate and the NiO thin film is deposited above on the micro heater to serve as sensing layer. Pt electrodes are formed below the sensing layer to measure the electrical conductivity changes caused by formaldehyde oxidation at the oxide surface. Furthermore, the upper sensing layer and NiO/Al2O3 co-sputtering significantly increases the sensitivity of the gas sensor, improves its detection limit capability. The microfabricated formaldehyde gas sensor presented in this study is suitable not only for industrial process monitoring, but also for the detection of formaldehyde concentrations in buildings in order to safeguard human health.