SSEF Bronze Award

Ellipsometry is an analytical technique utilizing polarised light to determine the property of ultra-thin film in nanometre range. In this project, a portable precision ellipsometry (PREL) system is constructed with the incorporation of new features on the modules and a core circuit based on a newly designed printed circuit board. It was used for analysis of water quality in publicly accessible water sources. We designed anchor layer (polystyrene sulfonate layer and polyethyleneimine layer) for attaching cations and anions to silicon substrate and measured the attachment using PREL. By analysing the attachments, we conclude that water contamination depends on locations and weather conditions, such as more contamination on sunny than on rainy day. This proves that PREL has high sensitivity of measuring molecular layers in sub-nanometre range. Portability of PREL allows measurements in the field and shows its great potential in water quality measurement and environmental monitoring.