Low-cost, handheld sensors for measuring environmental nitrates

The Problem: Increasing pressures on water resources have led to greater water scarcity and a growing demand for sufficient quantities of high-quality water for various potable and non-potable purposes. Water reuse (also known as water recycling or reclamation) reclaims water from various sources such as municipal wastewater, industrial and commercial process water, agricultural runoff, and stormwater. However, the current cost of tools to analyze the water quality is limited, and there is a need for passive, low-cost sensors to characterize the performance of nature-based solutions. The Innovation: PAGE Technologies develops chemical sensors that can be deployed directly into the environment for real-time measurement at a >100x lower cost than competing products. This suite of sensors detects key parameters, including pH, electrical conductivity, temperature, and specific chemical content (e.g., nitrate, potassium). The core breakthroughs of the innovation are twofold: (1) the manufacturing process and (2) device architecture. Scalable printing techniques are utilized to manufacture solid-state sensor arrays at low cost. Competition: The incumbent method for chemical analysis of environmental soil and water is to collect and ship samples to 3rd party laboratories for spectroscopic analysis. This process is labor intensive, expensive, and has a long delay in receiving the data. PAGE’s sensors acquire data in seconds with minimal labor and are more affordable than laboratory tests. Presently, PAGE sensors are less accurate than lab tests (~3% vs. ~15%), but only 15-20% accuracy is required for their intended use case. Commercial Potential: Low-cost chemical sensors that can measure water parameters - including specific ions - have potential in various markets due to their versatility and wide range of applications, including agriculture, conservation, and wastewater treatment. Customer discovery through the NSF I-Corps program unveiled controlled environmental agriculture (CEA) as an ideal beachhead market because the proposed sensors would resolve the pressing need for a low-labor method of analyzing their nutrient solution to optimize plant health and reduce dumping frequency. Impact: The affordability of the sensors enables wide distribution, thereby unlocking real-time environmental gradient mapping of key water parameters. This instant data enables immediate actionability to improve water quality, reduce pollutants, and evaluate different intervention strategies. Goal: This EPA SBIR Phase I proposal aims to improve the device-to-device (D2D) variability of PAGE’s chemical sensor technology and develop a handheld nitrate sensor MVP for environmental water monitoring. Furthermore, the MVP will be pilot-tested for environmental water monitoring by various stakeholders, including Bluelab, AquaRealTime, and VyCarb.