Researchers from the University Of Cambridge have recently discovered how the touchscreen technology, already used in billions of smartphones could also be used as a powerful sensor to identify contamination in water and soil.
Their research has shown how a touchscreen can be modified and used to identify common ionic contaminants in soil or drinking water. It works by simply dropping liquid samples onto the screen and then using a software to analyse the data. Using the same software they then tested a variety of different liquids and measured the change in capacitance (the ability of a system to store an electric charge). This therefore allowed them to detect any abnormalities within the liquid.
How does it work? The electrode design of the screen has been ‘tuned’ by the researchers and is able to detect these abnormalities in the electric charge of the liquid, as the screen has been optimised for sensing rather than the touch of our fingers.
It is hoped that an early application of the new technology could be to detect arsenic contamination in drinking water. Arsenic is a metalloid component of the Earth's crust and a common contaminant found in groundwater, however most water systems detect it and filter it out before it reaches a household tap. For the parts of the world which don’t have these water treatment systems in place, this contaminant can pose a real problem.
“For example, if we could get the sensitivity to a point where the touchscreen could detect heavy metals, it could be used to test for things like lead in drinking water. We also hope in the future to deliver sensors for home health monitoring,” said Dr Ronan Daly from Cambridge’s Institute of Manufacturing, who co-led the research.
Now ions can be detected using a touchscreen, researchers are looking to further develop the technology for a wide range of sensing applications such as biosensing or medical diagnostics as well as a wider range of molecules, straight from the phone in your pocket. This is largely beneficial as it has the potential for a huge range of potential health applications.
If you would like to read more the results are reported in the journal Sensors and Actuators B. If you’d like to read more in depth click on the article credit for more.