Compostable crop sensors target sustainable farm monitoring

Glasgow University is leading a new project to develop green electronics for connected farming, including biodegradable crop sensors and organic photovoltaics.

Jake Gard via Unsplash

The £1.8m international collaboration, called Transient Electronics for Sustainable ICT in Digital Agriculture, will feature researchers from Canada, Finland, Poland and Switzerland alongside the Glasgow academics. Over the next three years, the project will explore the development of a modular sensor system for crop monitoring, where the two constituent parts either biodegrade into the soil at their end-of-life or can be collected and reused in future systems.

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The sensor patch itself will be the biodegradable component. According to the team, the project will explore the use of materials such as rice husks and fibrous proteins like wool, as well as compostable polymers like cellulose and starch, embedded with conductive metal nanoparticles made from copper and zinc. Organic photovoltaics will be used to power the sensors, with energy stored in biodegradable supercapacitors rather than batteries, which have the potential to leach toxic elements into soil.

According to project coordinator Professor Ravinder Dahiya, from Glasgow’s James Watt School of Engineering, the sensors will be capable of tasks including monitoring pH, temperature and bioimpedance, giving farmers visibility over key metrics as crop yields across the globe come under increasing pressure from climate change.

Crops are coming under increasing pressure due to climate change - Raphael Rychetsky via Unsplash

“The internet of things has huge potential to revolutionise every aspect of human activity, from home lives to global industry,” said Professor Dahiya. “Harnessing the power of the internet of things is particularly attractive in farming, where the challenges of growing crops as we adapt to the unpredictable effects of climate change will require close monitoring of fields and quick responses to problems to maximise crop yields. 

“However, the proliferation of digital devices that underpin the internet of things is also leading to a massive expansion in digital waste. As much as 80 per cent of our electronic devices currently end up as waste. As potentially dangerous materials in components like batteries and printed circuit boards degrade, they create hazards to the environment and to human and animal health which can last for decades.”

The second part of the sensor system will be an electronic module equipped with wireless communication technology. A key priority of the design for this module is that it will be reusable and repairable in an effort to minimise waste from the overall system.

“What we’re setting out to do with this project is to build hardware which is designed from the start to be disposable without creating problematic waste,” Professor Dahiya continued. “In fact, the waste materials from our sensors will help to grow future crops of the plants they once monitored.   

“It’s an ambitious undertaking, but it brings together some of the leading experts in the field of sensor and material development from across Europe and North America. I’m confident that we can create prototypes with the potential to make real change and take us closer to achieving a zero-waste world.”

The research is funded by URKI in the UK, FRQNT in Canada, Academy of Finland in Finland, NCN in Poland and SNSF in Switzerland.