Compostable sensors could help grow impact of digital agriculture
Published: 1 April 2025
Screen-printed, biodegradable soil sensors which can be composted at their end of their lifecycle could enable farmers to improve crop yields while reducing electronic waste, researchers say.
Screen-printed, biodegradable soil sensors which can be composted at their end of their lifecycle could enable farmers to improve crop yields while reducing electronic waste, researchers say.
The sensors, developed by engineers from the University of Glasgow in collaboration with colleagues from the Łukasiewicz Institute of Microelectronics and Photonic (IMiF) are made from electronic materials which degrade into plant nutrients, acting as fertiliser to help crops grow.
The prototype biodegradable sensor the team have developed is on the left of the image, partially submerged in the soil. The reusable electronics which will help enable digital agriculture readings are connected by wires.
The research is a key development in a wider international project called TESLA, which stands for Transient Electronics for Sustainable ICT in DigitaL Agriculture. The £1.8m project is funded by UK Research and Innovation and CHIST-ERA, a consortium of research funding organisations in Europe and beyond.
TESLA is led by the University of Glasgow and brings together partners from McGill University in Canada; Tampere University and VTT Technical Research Centre of Finland Ltd in Finland; Łukasiewicz Research Network – Institute of Microelectronics and Photonics in Poland and the CSEM Centre Suisse d’Electronique et de Microtechnique SA in Switzerland.
The project aims to develop a complete system where the biodegradable sensors are powered by solar cells and supercapacitors also made from sustainable materials, enabling a fully environmentally friendly solution for precision agriculture monitoring.
The new technology aims to support global efforts to make food production more efficient and sustainable as populations grow and climate change presents new challenges for large-scale farming.
The biodegradable front-end sensors are paired with conventional electronics to monitor crop health. The team say their modular approach enhances the reusability of the overall existing electronic systems and significantly reduces electronic waste, resulting in a much lower overall environmental impact. Detailed environmental impact assessments conducted by the researchers shows that operating the electronics in this way improves sustainability.
Their modular, hybrid electronics architecture has been applied to ‘digital agriculture’, a new approach to farming which uses which uses networked sensors directly applied to crops to monitor their environment and their growth. Digital agriculture could help to meet the 70% increase in global demand for food that experts believe will be needed by 2050.
However, the current generation of sensors used in digital agriculture are made from non-recyclable materials. That means an expansion in the use of digital agriculture would also create an increase in environmentally harmful electronic waste when the devices reach the end of their lifecycles.
In a paper published in the journal ACS Applied Electronic Materials, the team describe how they made a digital agriculture sensor from sustainable materials, combining a biodegradable patch with a matchbook-sized reuseable electronic module. The sensor patches are manufactured using a screen printing process, similar to that used in t-shirt printing. This low-cost, low-energy method of manufacturing could help enable the large-scale deployment necessary for the wider adoption of digital agriculture around the world.
In this work, conductive tracks are printed onto a biodegradable polymer substrate using graphene-carbon ink. Then, a sensing layer made from molybdenum disulfide is printed on top – so all materials used naturally break down into plant nutrients.
Data from the sensors, which are sensitive to the changes in pH and temperature which can be caused by infections in crops, are collected by the electronic module. The data can be sent wirelessly to computers, which could in the future help farmers build up a detailed picture of the health of their crops.
Lab tests showed the sensors can reliably monitor soil pH levels, with consistent performance demonstrated in solutions ranging from pH 3 to pH 8 over the course of two weeks. The team also demonstrated that that the sensors can detect traces of ethephon, a widely used plant growth regulator that can be toxic to humans and wildlife if it contaminates groundwater. At the end of their useful lifecycle, the sensors degrade into key primary and secondary nutrients to support future plant growth.
Dr Joseph Cameron, of the University of Glasgow’s James Watt School of Engineering, is a co-author of the paper. He said: “Reliable food production is one of the world’s most pressing problems, with more than 800 million people around the world suffering from malnutrition today. Digital agriculture could be the key to maximising our ability to produce enough food for a growing population.”
Co-author Andrew Rollo, also of the James Watt School of Engineering, said: “The system we’ve developed could go a long way towards cutting down the carbon footprint of digital agriculture. The sensors themselves can be ploughed back into the fields to help nurture crops, and the electronic modules with less environmentally friendly printed circuit materials can be reused for several years.
“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 James Watt School of Engineering’s Professor Jeff Kettle led the research. He said: “We urgently need to find a way to make digital agriculture more sustainable in the years to come. 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.
“We’re keen to continue expanding our biodegradable sensor’s ability to detect other key indicators of plant growth and soil health. That could include adding sensitivity to ‘forever chemicals’ like PFAs, which have significant environmental impact.”
The team’s paper, titled ‘Hybrid agricultural monitoring system with detachable biodegradable and printed pH sensor with a recyclable wireless sensor network for sustainable sensor systems’, is published in ACS Applied Electronic Materials. Researchers from the Łukasiewicz Research Network – Institute of Microelectronics and Photonics and Central South University of Forestry and Technology co-authored the paper.
The research was supported primarily by funding from the Engineering and Physical Sciences Research Council (EPSRC), as well as the São Paulo Research Foundation (FAPESP).
First published: 1 April 2025