Researchers from the University of Cambridge showed how a typical phone’s touchscreen could be used to identify common ionic contaminants in soil or drinking water by simply dripping liquid samples onto the screen. The sensitivity of the touchscreen sensor is comparable to typical lab-based equipment, rendering it useful in low-resource settings.
The researchers say their proof of concept could one day be expanded for a wide range of sensing applications, including for biosensing or medical diagnostics.
While other research teams have utilised the computational power of smartphones for sensing applications, this is the first study to use the screen itself, rather than the camera or peripheral devices or significant additions to the screen. A typical phone screen is covered with a grid of electrodes; when a finger causes a local disruption in the electric field of these electrodes, the phone interprets this input signal.
“We wanted to know if we could...