Grantee Research Project Results
Final Report: Chemical Sensor-Modulated Transistors for Water Treatment Performance Monitoring
EPA Contract Number: 68HERC21C0009Title: Chemical Sensor-Modulated Transistors for Water Treatment Performance Monitoring
Investigators: Renna, Lawrence A
Small Business: Intelligent Optical Systems Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2021 through August 31, 2021
Project Amount: $99,961
RFA: Small Business Innovation Research (SBIR) - Phase I (2021) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Water , SBIR - Clean and Safe Water
Description:
Water is vital to human life, the environment, and the United States and global economies, but growing water scarcity is increasing the pressure on public health, the environment, and the economy. Thus, there is a clear and present need to advance water recycling and reclamation technologies. To that end, in February of 2020 the EPA announced the National Water Reuse Action Plan (WRAP) for municipal wastewater, industrial process water, stormwater, agriculture runoff, and oil and gas wastewater. Uses for the resulting potable and non-potable water include agriculture, groundwater storage, industrial processes, saltwater intrusion barriers, and environmental restoration.
Monitoring water treatment performance is essential for full implementation of WRAP. The continuous assurance of water quality during recycling is essential for recovery of both potable and non-potable water. Aging and failure of water decontamination systems have serious public health and environmental impacts, so performance monitoring is critical. Real-time monitoring is important to ensure the efficacy of water recycling systems, so rapid, selective, and sensitive sensing platforms are urgently needed to monitor contaminants, regulated chemicals, and disinfection byproducts.
Traditional lab-based analytical equipment for identifying water contaminants is bulky, expensive, and generally not practical for continuous detection. Furthermore, current portable water analysis gear, such as test strips, is limited in its sensitivity to certain analytes. Intelligent Optical Systems, Inc. (IOS) proposed to develop an extremely sensitive electrochemical sensor with selective/sensitive polymer membranes, in a handheld format. The sensor films will modulate the voltage of the extended gate electrode of an off-the-shelf field effect transistor, giving the device very high sensitivity to detect analytes at concentrations below the permitted levels.
Summary/Accomplishments (Outputs/Outcomes):
In this work we developed chemistries for chloroform, lead, mercury, and chlorpyrifos that all show an impedimetric response to their respective analytes, and thus can all be used in our sensor measuring device. The basis for our sensors is selective polymeric coatings and membranes that are sensitive to the aforementioned contaminants. We advanced our circuit through three design iterations (Gen 0, Gen 1, and Gen 2) and developed a low-noise, accurate, multiplexed sensor measuring system that has low size, weight, power, and cost. We also demonstrated the feasibility of using additive manufacturing to fabricate sensor arrays. Finally, we integrated our sensors and electronics into a prototype with a handheld housing for the system.
We developed sensor chemistries that demonstrated operation in the following concentrations: 94.5 ppt=960.0945 ppm lead, 70 ppt=967.0 ppm mercury, 2 mg/mL=968 mg/mL chloroform, and 1.05 ppm=961051 ppm chlorpyrifos. The Gen 2 design was developed on a multiplexed custom circuit board with three chemical sensor channels and one internal reference channel, as well as temperature and humidity sensors. Gen 2 is handheld and has improved performance=BEhigher bandwidth, greater accuracy, and decreased noise. We determined the aerosol jetting parameters to print silver electrodes and our sensor formulations. Finally, we determined a method of integrating the sensors and electronics into a handheld prototype.
Conclusions:
All objectives were met during this Phase I work, and the technical feasibility of the proposed sensor system was demonstrated. We believe that our technology fits directly within the EPA's core mission of protecting human health and the environment. Additionally, we understand that the goal of the SBIR program is to turn ideas that fit within this framework into successful, revenue generating businesses. IOS estimates cumulative sales revenues of $41.3M and cumulative pre-tax net-profit of $17.3M during the first five years of commercialization.
Commercial viability of the product under development was demonstrated by thoroughly evaluating major needs for a handheld sensor system, mainly in the wastewater treatment market. The wastewater treatment services market size is projected to reach USD 65.1 billion by 2024 from an estimated USD 48.5 billion in 2019, at a CAGR of 6.1%, indicating a large market for our device. Our market analysis revealed there is a strong need for a heavy metal sensor system that is handheld, fast, sensitive, and accurate. Interviews and analysis did not reveal a strong desire or market for sensors for halomethanes or organophosphates. We will use this information to focus our technology development to address the market desires and needs. Our value proposition is: a low-cost, accurate, handheld, lightweight, low power device that will display instantaneous and clear readings of contamination levels of heavy metals that municipal wastewater treatment facility operators and inspectors can use to obtain real-time water quality data. Inspectors at municipalities and other wastewater treatment facilities will adopt the new handheld water monitor sensor because it would save them tens of thousands of dollars in water quality testing/monitoring by delivering accurate results into the hands of the user to validate process control and closely monitor treatment performance. We have a unique technology that by offering accurate and low cost results in real time, could find several applications for use. Regulations are pushing industrial operators to monitor water quality on a real-time basis, which is an advantage and opportunity we can leverage.
Through our discussions with experts, we validated the need for a low-cost, accurate, handheld, lightweight, low power water monitoring system that will display instantaneous and clear readings of contamination levels at municipal wastewater treatment facilities. The municipal segment also accounts for the largest share of the total wastewater treatment services market, in particular rural facilities, which may need to validate the quality of their water on-site because getting results back from remote locations would be inefficient and time consuming. We also identified potential applications in other sectors such as agricultural, mining nuclear wastewater, and power plants markets.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.