AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Towards a Highly-Integrated Low-Cost PM Sensor
PAUL MAIERHOFER, Georg Röhrer, Jaka Pribošek, Gernot Fasching, Anderson Singulani, Harald Etschmaier, Martin Kraft, Alexander Bergmann, Graz University of Technology
Abstract Number: 405 Working Group: Air Quality Sensors: Low-cost != Low Complexity
Abstract Increasing awareness about the adverse health effects of particles in the air and stricter regulations on the part of the legislation lead to greater demands on the measurement and monitoring of air quality with respect to particle concentration. Up to now, a close-meshed and wide-area monitoring has failed due to the size, usability and cost of currently available sensors. We show our approach to build a highly integrated, cost-effective, maintenance-free and easy-to-use particle sensor for mobile applications. While space is limited, the necessary complexity of a total miniaturized sensor system is still similar to its handheld counterparts. Optical elements for the light scattering based sensor element, a suitable flow path for the ambient air, a pump to cause the airflow and the electronics – all within a package of roughly 12 x 9 x 2 mm3. We show our design of the sensor including the package with an integrated impactor, and the optical sensor element consisting of a VCSEL as a light source, a beam guiding structure, a photodiode, and a beam trap. Microfluidic considerations and simulations lead to an optimized interaction of the flow path with the optical elements. The package itself is coated with a highly light absorbing material in order to minimize stray light effects and to enhance the capability of the light trap. This minimization of stray light is a crucial step towards a functional sensor, as the signal scattered from the particles has to dominate over the stray light from other surfaces. We also show the concept for integrating a micro-pump in the system as well as an overview of selected challenges along the way such as the manufacturing of the prototypes. First measurement results utilizing PSL spheres of various sizes will be shown to evaluate the capabilities of the sensor.