Multi-Analyte VOC and Stressor Sensing Node for Plant Health Monitoring

We propose an integrated system which includes an array of printed amperometric sensors for detection of methanol, ethylene and other VOCs indicative of plant health in growth chambers. This array of sensors will be printed on a thin polycarbonate film, leveraging processes developed for our standard SPEC Sensor air quality sensors. Since amperometric sensors are essentially fuel cells, power requirements will be negligible, easily powered by small solar cells and ambient light. Successful completion of this project will result in a flexible, self-powered plant health sensor that can be attached to plant leaves or integrated into the in-flight plant growth chamber hardware. This system will allow spaceflight personnel to identify problems early so they can take corrective action before crop health, productivity, and safety are negatively affected. The overall technical objectives of this project are: design, development and test in laboratory (Phase I) and real-world environment (Phase II) a low-power, accurate and lightweight sensor for monitoring the transpiration of VOCs indicative of plant growth and health, as well as the climate-related stressors in the chamber. The sensors must be sensitive to low-ppb concentrations, and accurate over a range of environmental conditions, including operation in microgravity and compatibility with cabin atmospheres Successful completion of Phase I will provide path toward a Phase II demonstration. A successful Phase II will demonstrate measurements that are reliable indicators of plant health, with deliverable prototypes for NASA testing, ready for in-flight demonstration. In addition to the NASA in-space applications, this new technology will be valuable for the rapidly growing greenhouse and "vertical farming" markets. These markets are expected to increase even more rapidly as population growth and climate change deplete available farmland.
Benefits: Our first priority is to develop a sensor that meets all of the NASA requirements for plant health and growth in spaceflight and future colony plant production chambers. The technology developed will also expand utility of amperometric gas sensors to other electrochemically active components in confined space environments. Such chemicals which are not currently measured reliably with aqueous-electrolyte based EC sensors include: CO2, acetone and other ketones (body metabolites), ammonia, and organic acids (from waste and metabolic processes). There are broad commercial applications for technology resulting from this work, even larger in the near-term than the NASA requirements: * Greenhouses and the rapidly growing “Vertical Farming” Market * Improved Building air quality, "smart-building" networks These will be even larger near-term markets for the new and innovative sensor arrays. In 2022 the indoor farming market – greenhouses, hydroponics and aeroponics - in the US was valued at $5.1B, and worldwide at $38B. The worldwide market is anticipated to reach over $55B by 2032! The growing world population compounded with the rapidly decreasing arable space is expanding the market scope, and vertical farming is gaining popularity due to its higher yield than conventional farming.