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04/28/2026 | Press release | Distributed by Public on 04/28/2026 09:14

Stick-on Gel Offers New Way to Treat and Monitor Plants

Published Date

April 28, 2026

Article Content

A stick-on gel for plants could one day offer a simple, safe and targeted way to treat diseases and pests. Engineers at the University of California San Diego have developed an adhesive gel that can be loaded with substances, such as small molecule drugs or nanoparticles, and applied directly onto a plant to deliver those materials into its tissues. In tests, a gel loaded with antibiotics cleared a bacterial infection in a plant within about 48 hours.

Researchers, led by Nicole Steinmetz and Jinhye Bae, professors in the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering at the UC San Diego Jacobs School of Engineering, published their findings in Science Advances.

A key advantage of this gel is that it sticks easily to a wide range of plant surfaces, including both smooth and hairy leaves and stems. This is something existing adhesives struggle to do. Plant surfaces in general are difficult to adhere to. They change as plants grow and are protected by waxy, water-repellent layers.

To create their gel, researchers used a combination of two polymers: polyacrylamide, a stretchy material that provides strength and flexibility, and chitosan, a naturally derived material that forms strong yet reversible chemical bonds with plant surfaces. The result is an adhesive gel that conforms to the plant and stays in place even in rain. It can be removed and reapplied without damage. Plus, it is transparent enough to allow normal photosynthesis.

The gel can also deliver its cargo throughout the plant, not just at the point of contact. To demonstrate, the researchers loaded the gel with tiny fluorescent particles called quantum dots and placed it onto a leaf. Within four hours, the quantum dots were observed to have traveled through the plant's veins.

"It's exciting to see that a tiny patch, just a few millimeters wide, could have systemic effects in the plant," said study co-first author Zhecun Guan, a chemical and nano engineering Ph.D. student in the research groups of both Steinmetz and Bae. The gel could make plant treatments more targeted and less wasteful than sprays, for example.

The gel also opens new possibilities for human-plant interaction. In one experiment, researchers loaded the gel with ions and used it to attach a wire to a Venus flytrap. The other end of the wire was connected to a wearable device that generates a mild electrical signal when a user taps it. That signal traveled through the gel and into the plant, causing it to close without being touched. This proof-of-concept experiment demonstrates a way to remotely send signals between humans and plants.

Zhecun Guan, a chemical and nano engineering Ph.D. student at UC San Diego and co-first author on the study, applies a strip of adhesive gel onto a plant leaf.
The adhesive gel can be applied to various plant surfaces, including the top side (left) and underside (right) of a leaf.

"If plants had a way to communicate with us, we could respond faster to potential biotic and abiotic stressors," Steinmetz said. "This kind of technology has tremendous potential for improving how we protect crops and monitor the environment. We could also envision using this technology to harvest energy directly from plants and integrate it into the grid. These are just some of the exciting possibilities to explore in the area of human-plant interaction."

Side-by-side views of the gel attached to a plant leaf under normal light (left) and UV light (right).

In future work, the researchers plan to experiment with other types of cargo in the gel, such as cells or genetic material. Their goal would be to explore using plants as low-cost bioreactors that produce useful compounds like medicines.

Full study: "A strong, reversible, and conformal adhesive gel for diverse plants."

This work was supported by the National Science Foundation through the UC San Diego Materials Research Science and Engineering Center (MRSEC, grant DMR-2011924) and a Translational Research Institute for Space Health (TRISH) fellowship through NASA Cooperative Agreement NNX16AO69A.

Disclosures: Jinhye Bae, Jiayu Zhao and Nicole Steinmetz are the inventors for a pending U.S. patent application (no. 63/885,714) related to the work in this manuscript, filed 22 September 2025 through the UC San Diego Office of Innovation and Commercialization. Steinmetz is a cofounder of, has equity in, and has an interest in Mosaic ImmunoEngineering Inc. Steinmetz is a cofounder and CEO of, has equity in, and has an interest in PlantiosX Inc. Steinmetz is a cofounder and the manager of Pokometz Scientific LLC, under which she is a paid consultant to Ring Therapeutics Inc. The authors declare that they have no other competing interests.

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