Robust, Ion-Selective Thick-Film Sensors for Long Term Field Deployment
Lead Research Organisation:
University of Southampton
Department Name: Electronics and Computer Science
Abstract
The source of all water in land based water courses and water systems is rain, which in turn predominantly arises due to evaporation from seas and oceans. It is therefore not surprising that the most abundant electroactive species present in land based water bodies is the chloride ion although the concentration of chloride varies with the distance from the sea. A chloride sensor would therefore be an invaluable tool for hydrology since it offers a direct and simple method to track and map the flow of water as it moves through the terrain. Moreover selective and considered spatial distribution of chloride sensors (networks) will enable quantitative measures of the chloride retention capacity of different soil types and is therefore a useful tool for soil scientists. Furthermore, a chloride sensor gives a qualitative measure of soil salinity; a particularly important indicator for agricultural management. In addition, at the plant level a miniaturised array of chloride sensors would facilitate real-time studies of chloride fluxes in the root rhizosphere enabling new bioscience to be achieved. Other major species present in the environment include nitrate, which can be viewed as beneficial or as a contaminant depending on its location and concentration. Currently it is not possible to measure nitrate reliably in the field in real-time. A nitrate sensor has obvious benefits in the fields of agriculture, soil science and plant science. Again, at the root level it allows real-time measurements of nutrient fluxes to and from the plant.
We shall use thick-film screen printing technology to produce an array of sensors that measure chloride ions and nitrate ions with respect to an integrated reference electrode.
We shall use thick-film screen printing technology to produce an array of sensors that measure chloride ions and nitrate ions with respect to an integrated reference electrode.
Technical Summary
We shall develop an array of electrodes to measure chloride and nitrate ions with respect to an integral reference electrode. This shall be implemented using some novel developments in thick-film technology. Screen printing technology (thick-film) involves the layer by layer construction of a sensor on a common substrate using different materials deposited in patterns that define the required structure. Typically the printable materials are glass based and are processed at temperatures of the order of 850 degC, though lower temperatures are necessary for some materials. The majority of the screen printable materials employed are commercially available, but novel sensing materials will need to be developed in-house. With this technology, resulting sensors are inherently low cost due to the nature of the batch printing process and robust due to the glassy construction on a ceramic substrate.
When these sensors are coupled with emerging technologies in wireless networks, wide scale real-time measurement systems become truly viable for the first time. This project will demonstrate a simple proof of concept to show that such sensors can be employed in real environmental applications.
When these sensors are coupled with emerging technologies in wireless networks, wide scale real-time measurement systems become truly viable for the first time. This project will demonstrate a simple proof of concept to show that such sensors can be employed in real environmental applications.
Planned Impact
Impact Summary
Who might benefit from this research?
As the output from this project is an enabling technology, there are many potential beneficiaries. The enabling technology is sensors that can be deployed at different scales, allowing both temporal and spatial data to be collected. The obvious beneficiaries are those who would like to make use of the data that these sensors can generate, and these include scientists operating in the fields of biology, soil science, hydrology and environmental science. Specifically, there are many beneficiaries in the theme area of food sustainability. For example, detailed studies of plant behaviour in the presence of the selected measurands can be evaluated (e.g. assessing salt tolerance of plants) leading to developments allowing poor quality land to be used for agriculture.
The new science enabled by these sensors will indirectly benefit government agencies, regulators, policy makers and other stakeholders. For example, the mapping of the movement of fertiliser elements through different soil types will allow holistic, catchment area scale measurements to inform land use planning.
How might they benefit?
In the themes of food sustainability, soil science and hydrology, scientists benefit because the sensors (coupled with networks) allow unprecedented spatial and temporal data collection, allowing the effects of transient events to be monitored for the first time. This will allow scientific insights into such effects as diurnal variations in nutrient levels, impact of significant rainfall events (storms and floods), preferential use of nutrients due to local changes around a root, etc.
Other stakeholders (such as farmers and local populations) will benefit from the more intelligent use of resources, such as fresh water and fertilisers. Irrigation systems can be made more responsive and could potentially use brackish water for irrigation at certain times of the year. Real-time measurements of nutrient levels and their distribution will help farmers manage their fertiliser requirements with the added benefit of reducing eutrophication of waterways due to excess nutrient run off.
Moreover, there is a potential socioeconomic impact as well. The ability to measure environmental parameters at this level potentially allows field monitoring to a higher level than previously possible. Such potential impacts resulting from this include feedback systems allowing brackish water to be used for irrigation, thus reducing the strain on potable water supplies for parts of the world where potable water and irrigation are in competition, and as previously mentioned, informing on efficient farming practices to increase the amount of useable land, thus benefitting the population of these areas in general.
Impact within BBSRC Strategic Priorities
Soil science and agri-systems approaches: This work will allow improved understanding of agricultural systems as it enables research- based management systems at a range of scales (farm, catchment, regional) to optimise food production in ways that are reconciled with maintaining biodiversity. It also enables agri-ecosystem approaches to land management practices that enhance biodiversity conservation in agricultural and associated ecosystems.
Crop science: The developed sensors will have application in enhancing crop productivity and quality by allowing the optimised and efficient use of resources (e.g. water, fertiliser and human resources).
Living with environmental change: Increasing competition for water resources, coupled with reduced rainfall and increasing temperatures due to climate change are exacerbating water quality problems in many developed and developing countries. These sensors will allow hydrological models to be validated thus creating opportunities that bridge climate and ecosystems science, for example in the interaction of soil and water.
Who might benefit from this research?
As the output from this project is an enabling technology, there are many potential beneficiaries. The enabling technology is sensors that can be deployed at different scales, allowing both temporal and spatial data to be collected. The obvious beneficiaries are those who would like to make use of the data that these sensors can generate, and these include scientists operating in the fields of biology, soil science, hydrology and environmental science. Specifically, there are many beneficiaries in the theme area of food sustainability. For example, detailed studies of plant behaviour in the presence of the selected measurands can be evaluated (e.g. assessing salt tolerance of plants) leading to developments allowing poor quality land to be used for agriculture.
The new science enabled by these sensors will indirectly benefit government agencies, regulators, policy makers and other stakeholders. For example, the mapping of the movement of fertiliser elements through different soil types will allow holistic, catchment area scale measurements to inform land use planning.
How might they benefit?
In the themes of food sustainability, soil science and hydrology, scientists benefit because the sensors (coupled with networks) allow unprecedented spatial and temporal data collection, allowing the effects of transient events to be monitored for the first time. This will allow scientific insights into such effects as diurnal variations in nutrient levels, impact of significant rainfall events (storms and floods), preferential use of nutrients due to local changes around a root, etc.
Other stakeholders (such as farmers and local populations) will benefit from the more intelligent use of resources, such as fresh water and fertilisers. Irrigation systems can be made more responsive and could potentially use brackish water for irrigation at certain times of the year. Real-time measurements of nutrient levels and their distribution will help farmers manage their fertiliser requirements with the added benefit of reducing eutrophication of waterways due to excess nutrient run off.
Moreover, there is a potential socioeconomic impact as well. The ability to measure environmental parameters at this level potentially allows field monitoring to a higher level than previously possible. Such potential impacts resulting from this include feedback systems allowing brackish water to be used for irrigation, thus reducing the strain on potable water supplies for parts of the world where potable water and irrigation are in competition, and as previously mentioned, informing on efficient farming practices to increase the amount of useable land, thus benefitting the population of these areas in general.
Impact within BBSRC Strategic Priorities
Soil science and agri-systems approaches: This work will allow improved understanding of agricultural systems as it enables research- based management systems at a range of scales (farm, catchment, regional) to optimise food production in ways that are reconciled with maintaining biodiversity. It also enables agri-ecosystem approaches to land management practices that enhance biodiversity conservation in agricultural and associated ecosystems.
Crop science: The developed sensors will have application in enhancing crop productivity and quality by allowing the optimised and efficient use of resources (e.g. water, fertiliser and human resources).
Living with environmental change: Increasing competition for water resources, coupled with reduced rainfall and increasing temperatures due to climate change are exacerbating water quality problems in many developed and developing countries. These sensors will allow hydrological models to be validated thus creating opportunities that bridge climate and ecosystems science, for example in the interaction of soil and water.
Publications
Nick Harris (Author)
(2013)
Overview of recent developments in smart, wireless, real-time, networked microsensors
Description | This award has lead to the development of a new type of chloride sensor for use in environmental monitoring. The novelty of the produced device is that it includes a newly developed planar reference electrode, that can be printed, at the same time and on the same substrate as the active sensor. This makes a complete sensing structure that can be printed. Previously all reference electrodes have been separate entities. In addition the ability to print this onto industry standard ceramic substrates makes these sensors very robust and potentially low cost, and thus well suited to distributed sensing. As a demonstration of this, the chloride sensors have been trialed in greenhouses in Australia and have already revealed new insights into the movement of chloride through soils over short temporal periods. Further, initial trials of the sensors in a deployment in a catchment in Luxembourg have been successful, and a further trial took place in Summer 2017, with bespoke data reporting nodes designed to match the sensors, giving a low power environmental chloride monitoring system. The results from this are currently being analysed. |
Exploitation Route | The findings are being taken forward in a collaboration between myself, Luxembourg Institute of Technology and University of Western Australia. This has resulted in a trial deployment in Luxembourg that has allowed new insights into modelling the movement of water though this area (currently being written up). As a result of this, we are reporting some findings to the EGU annual assembly again in May, and are planning further trials this year. |
Sectors | Agriculture, Food and Drink,Chemicals,Electronics,Environment,Government, Democracy and Justice |
Description | Due to this award and its publications, there has been more interest in Southampton's capability in sensor development for environmental applications, and we are assisting a local company (City Farm Systems) in instrumenting a technology demonstrator for growing crops near to the point of sale. I have also been asked to present based on this work at a public event in Southampton in May 2017. |
First Year Of Impact | 2016 |
Sector | Agriculture, Food and Drink |
Impact Types | Economic |
Description | New technologies and enhanced techniques for water resource assessment in a changing climate |
Organisation | University of Western Australia |
Country | Australia |
Sector | Academic/University |
PI Contribution | In this WUN collaboration I provided new sensors and logging systems and carried out experiments on site in Australia |
Collaborator Contribution | Collaborators provided access to field sites and test facilities in parts of Western Australia, and also provided advice and guidance to PhD students here. |
Impact | Another WUN application has been submitted -outcome unknown as of 5/11/2014 Joint publications as listed in outputs section |
Start Year | 2013 |
Description | A box of tricks set to revolutionise soil-based salinity measurements. |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | Yes |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | The sensors developed in this project were used in field trials in Australia, and this reports this. http://www.ioa.uwa.edu.au/__data/assets/pdf_file/0019/2461501/110666_IOA-newsletter-Dec-2013-WEB.pdf p14 no actual impacts realised to date |
Year(s) Of Engagement Activity | 2011 |
URL | http://www.ioa.uwa.edu.au/__data/assets/pdf_file/0019/2461501/110666_IOA-newsletter-Dec-2013-WEB.pdf... |
Description | Wireless Networks for Monitoring Applications |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Professional Practitioners |
Results and Impact | Presentation to a regular meeting of the Institute of Engineers in Perth, WA This presentation will discuss the attraction of wireless sensor networks together with the requirements for use in environmental monitoring. An example of a new sensor technology, originally developed to detect chlorine in corrosion monitoring applications, but now being assessed for application in monitoring salinity in waterways in Western Australia will be presented. The principles and ideas of the sensor were presented recently at the Riversymposium in Brisbane. no actual impacts realised to date |
Year(s) Of Engagement Activity | 2014 |