Scientists develop silk microneedles to deliver nutrients and chemicals to plants

When farmers apply pesticides to their crops, 30 to 50% of the chemicals end up in the air or soil instead of on the plants.

Now, a team of researchers from MIT and Singapore has developed a much more precise way to deliver substances to plants: tiny needles made of silk.

In a study published in Nature Nanotechnology, the researchers developed a way to produce large amounts of these hollow silk microneedles. They used them to inject agrochemicals and nutrients into plants, and to monitor their health.

"There's a big need to make agriculture more efficient," says Benedetto Marelli, the study's senior author and an associate professor of civil and environmental engineering at MIT. "Agrochemicals are important for supporting our food system, but they're also expensive and bring environmental side effects, so there's a big need to deliver them precisely."

In demonstrations, the team used the technique to give plants iron to treat a disease known as chlorosis, and to add vitamin B12 to tomato plants to make them more nutritious. The researchers also showed the microneedles could be used to monitor the quality of fluids flowing into plants and to detect when the surrounding soil contained heavy metals.

Image source: Cao et al. (2025), Nature Nanotechnology.