Palestrante:  Profa. Dra. Mahnaz Shafiei

Swinburne University of Technology, Australia

Título: "Portable and Low-Power Nanostructured Gas Sensors”

Abstract:

Sensor technology is an important enabler in modern society for detecting, monitoring and managing phenomena in our natural and built environments. This is evident in the need for detection of trace toxic analytes and explosive gases for public safety and security, healthcare, transportation, industrial processes and monitoring of environmental pollution and air quality. A revolutionising technological trend is the rapid growth of mobile sensors for personalised health evaluation, environmental monitoring, robotics and security. Portable gas sensors are of critical importance for the detection of air pollutants, greenhouse gases and chronic or disease-related biomarkers in human breath such as NH₃, NO₂, CO₂, CO, CH₄ and volatile organic compounds (VoCs). The ultimate goals of research into the next generation of gas sensors are (i) to miniaturise the devices and (ii) to operate with low power requirements. These goals allow for longer term operation of mobile sensors to provide, for example, real-time data about ambient air quality and health monitoring.

In the emerging fields of Nanoscience and Nanotechnology, research and development in gas sensors has achieved significant progress. However, the development of portable gas sensors operating at room temperature (RT) with high performance is still challenging. A gas sensor working at RT is very appealing; in particular, when battery operated wireless sensors are required. This capability implies that they don’t require a heater for high temperature operation of the sensing layer and therefore, will have very low power consumption. This strategy would simplify the fabrication process, reduce operational costs and should allow extensive use in many different settings.

This talk will focus on nanotechnology to develop miniature, inexpensive, low-power gas sensors with high performance for sustainable use in health and environmental monitoring. In this research, novel sensing materials including CuTCNQ, CuTCNQF₄, functionalised graphene oxide (GO), carbon nanotubes, 2D nanomaterials including WO₃-rGO, SnS₂-rGO and TiO_x as well as electrospun porous WO₃ nanofibres have been synthesised and employed in conductometric devices for gas sensing applications. These novel sensors can be embedded in sensor nodes for the Internet-of-Things (IoT) applications or in mobile systems (for continuous monitoring of air pollutants and greenhouse gases. These gases occur in many environments and, even in trace amounts, are key indicators of human, animal, plant and environmental health. The sensors can be deployed over vast areas to monitor air quality inside buildings or in metropolitan areas or to improve energy efficiency in green buildings.