Grant: Discovery Grants Program - Individual

With a notable recent drive to reduce Canada's reliance on imported fresh produce and build the resilience of food systems, automating the greenhouse growing environment has become an important step toward this goal, which can increase the efficiency of greenhouse operation to a new level. This step, however, distinctly relies on developing autonomous, cost-effective, portable, and most importantly sensitive early-stage detection system to prevent greenhouse product losses resulting from pests. Such early pre-emptive intervention has a tremendous impact on personal health and wellbeing as well as Canada's economy as a producer of greenhouse products. Current methods for identifying greenhouse pests mainly rely on manual scouting, or in special cases gas chromatography-mass spectrometry (GC-MS) technique. However, both methods are labour-intensive and fall short in autonomously detecting the invasive forces. In addition, many existing vision-based monitoring systems also have limitations in detecting pests at an early stage since a visible sign must appear on the surface of the product before detection is possible. Other commonly used detection methods in the agricultural field including carbon dioxide and temperature monitoring are also deemed nonviable for greenhouse pest detection application due to the nature of the greenhouse environment. This research program proposes an innovative mass resonator as an emerging technology that can deliver a cost-effective autonomous solution for greenhouse pest detection at an early stage. Unlike existing greenhouse monitoring technologies, this work targets measuring the pests' signature volatile organic compounds (VOCs) associated with their stage of life and population. Such detection mechanism will lower the detection pest limits in a greenhouse ecosystem where the product losses can be reduced far below present levels. The unifying theme of this program is to exploit the unique opportunity given by an unconventionally designed flexible platform functionalized by an absorber, that is a recent patented discovery in the applicant's research lab. The proposed micromachined mass sensor utilizes an additional fixed to free boundary ratio design parameter in its topology that results in a complex but potent method to optimize the sensor structure. This technique can greatly extend the limit of detection for pest volatile detection applications. In addition, utilizing the optimized fixed to free boundary ratio approach of the flexible plate results in retaining the sensor's selective absorber active area while enhancing the device center frequency and sensitivity. Furthermore, this technology benefits from the inheritably flexible micro electrotechnical systems (MEMS) fabrication technique, which can reduce cost and tighten parameter specifications. Moreover, this approach has the potential for future expansion to wider applications such as medical and environmental science.