Gas Sensors for a Sustainable Society
ABSTRACT
The global gas sensors market has showed rise in demand for sensors for real-time monitoring of gas concentrations and on industrial health and safety. Sensors with limited sensitivity and selectivity for certain gases, false alarms and interferences remain as market restraints. Current gas sensors market is still mainly represented by electrochemical sensors but we are seeing a growing trend in technologies such as non-dispersive infrared (NDIR) and metal-oxide semiconductor (MOS) sensors.
With more activities in sustainability and adoption of renewable fuel, hydrogen (H2) and ammonia (NH3) become potential candidates for consideration either to replace fossil fuel or as a carrier for H2. These potential candidates are flammable and explosive, with NH3 being toxic. There is therefore a need for reliable gas sensors for these sustainable fuels, either to monitor their purity concentration or to sense leakage for safety mitigation. In addition to sensors for sustainable fuels, sensors for greenhouse gas emissions monitoring continue to be of importance to understand their impact on climate changes.
In this talk, I will discuss current and emerging technology trends of gas sensors, how gas sensors can add value to our efforts towards a sustainable society, the different areas of sustainability that these sensors can come in and their use cases. One sensor does not fit all. The key is to leverage on the key characteristics of each sensor technology, their advantages and disadvantages for different applications. I will also introduce some of the gas sensors prototypes developed by IME that are applicable in the sustainability domain. In particular, we have developed H2 purity sensor for high concentration in-line H2 purity measurement and H2 leakage sensor for safety. Our thumb-size H2 purity sensor measures H2 at high concentration (90%-100% concentration) and has shown resolution of ~0.1%. This is useful for in-line real-time H2 monitoring and are useful to be integrated with hydrogen production systems such as electrolyzers. Our H2 leakage sensor has shown response down to 20 ppm, well below H2 lower explosion limit of 4%. Both sensors have high selectivity to H2 and are expected to be non-poisoning.
BIOGRAPHY
Doris Ng joined Data Storage Institute at A*STAR (Agency for Science, Technology and Research) in 2007 and worked on integrated photonics devices and platforms for more than 10 years before moving to Institute of Microelectronics (IME) at A*STAR in 2018 where she joined the Sensors, Actuators and Microsystems department. At IME, she takes on a major role in the development of photonics-based gas sensors, MEMS ScAlN-based pyroelectric detectors and using them for NDIR gas sensing. She has published >100 papers with >1000 citations and is on World’s Top 2% Scientists list by Stanford University in 2023. Her research interests include pyroelectric devices, optical and thermal conductivity gas sensors using pyroelectric devices and development of chemical and gas sensors required for a sustainable economy.
Doris is currently the Deputy Head of Department for Photonics & Sensors Department in IME and also leading the chemical and gas sensors efforts in this department. She is actively on the reviewer panel for journals such as Sensors & Actuators B: Chemical, Advanced Science, Advanced Photonics Research and ACS Sensors. Doris received her Ph.D. degree in Engineering from the National University of Singapore (NUS), Singapore in 2008.