Sustainable sensor guards plant health and feeds the soil

Engineers from the University of Glasgow and Poland’s Lukasiewicz Institute of Microelectronics and Photonic (IMiF) have created a form of biodegradable sensor which say they combines productivity with sustainability.

Describing the project in ACS Applied Electronic Materials, the scientists say their invention represents an advance on current forms of ‘digital agriculture’ by employing recyclable materials.

Research leader, professor Jeff Kettle of the James Watt School of Engineering, explained: “Currently, around 80% of the world’s electronics head straight to landfill once they’ve reached the end of their useful life, which creates massive environmental and public health challenges from the toxic materials which many of them contain.”

Using a screen printing process, they fashioned a biodegradable patch, combining it with a “matchbook-sized” reusable electric module capable of forwarding data from the field to a computer.

Conductive tracks were applied to a polymer substrate, with the aid of graphene carbon ink, topped with a sensing layer created from molybdenum disulfide.

The sensor is able to measure temperature and plant soil pH levels that might indicate the presence of crop infections. Its lifecycle concludes with the technology breaking down into nutrients that further benefit growth, say the researchers.

Kettle’s James Watt School colleague and co-author Andrew Rollo, outlined the possible environmental benefits:

Said Rollo: “Our analysis suggested that replacing the sensors once every three months could reduce the environmental impact of the system by 66%, and 79% over five years compared to disposing of the entire device each time.” 

The duo’s co-author Dr Joseph Cameron pointed out the potential productivity and public gain, pointing out that reliable food production remained a key global challenge which digital agriculture could tackle. Currently, he said, some 800 million of the world’s population suffered from malnutrition.

There is hope also that the sensor technology could further contribute to crop efficiency, said Kettle. The researchers plan to expand the sensor’s range of key indicators including ‘forever’ PFA chemicals.