The team of researchers developed their bionic plants to identify explosives in soil. When landmines are buried, they emit nitroaromatics, which a spinach plant’s roots can sense. To turn this natural sensation into signals usable by humans, the engineers inserted carbon nanotubes into spinach roots. If the plants detect contamination in the soil, the tubes emit a signal, which is then picked up by an infrared camera. An email alert goes to scientists to warn them about the explosives.

This is just one use of plant nanobionics – a field of research that explores inserting electronic components into plants to produce new abilities. There’s potential for a similar sensor system to monitor soil quality and identify climate change markers (for details on soil’s importance, see How Soil Will Save the World). “Plants are very environmentally responsive. They can detect small changes in the properties of soil and water potential,” said Professor Michael Strano, who led MIT’s research. “If we tap into those chemical signalling pathways, there is a wealth of information to access.”

High levels of organic compounds in plants make them suitable for a range of applications. Researchers at American University (Washington DC) chose spinach – which is highly conductive thanks to its high quantities of iron and nitrogen – as a raw material to increase efficiency in metal-air batteries and fuel cells. When ground down into a powder, the spinach can be turned into a nanosheet. This sheet is inserted into batteries to catalyse the chemical reactions required to produce power.

For more on the food industry’s tech-filled future, see Food Tech Trends to Watch 2021.