The hidden chemistry behind safer swiping

In the age of smartphones and tablets, swiping and tapping have become second nature. Billions of people around the world do it every day, yet few consider what materials make that experience possible. And even fewer realize that excessive swiping, over time, could expose them to toxic chemicals.  

That’s because some smartphone screen coatings designed to resist smudging may contain per- and polyfluoroalkyl substances (PFAS), which evidence suggests are harmful to human health and the environment. Often called “forever chemicals,” PFAS don’t break down easily and can persist in the body. According to a 2025 report by Environment and Climate Change Canada and Health Canada, exposure to these substances is linked to potential adverse effects on the liver, kidneys and immune function, among other systems and organs.

“If the coating wears down on the screen glass, there’s exposure risk through touch,” says Kevin Golovin, an associate professor in the Department of Mechanical and Industrial Engineering at the University of Toronto. “While it’s bonded to the screen, the coating can eventually rub off after repeated swiping or if the screen breaks.”

Greater understanding of the toxicity of PFAS, along with consumer demand for eco-friendly products and stricter government regulations, has made finding safer, non-toxic alternatives a priority for both industry and researchers, including Golovin.  

With $125,000 in funding from the Acceleration Consortium’s Accelerate Seed Grant, and in collaboration with Professor Frank Gu in the Department of Chemical Engineering & Applied Chemistry, Golovin has started to build a self-driving lab (SDL) with the aim of finding and formulating non-toxic anti-fingerprint coatings for smartphone screens.

“I was made aware of the problem by one of our industrial collaborators who manufacture the phone glass,” Golovin explains. “I didn’t realize that there was a fluorinated compound on the glass, and part of my lab’s research is finding replacements for that type of material.”  

So far, Golovin has used the SDL to create a fully autonomous system capable of simulating the abrasion and pressure of repeated swiping on screen glass. This system can swipe thousands of times a day and characterize and test the durability of PFAS-free coatings.  

“We’ve been targeting silicones, which have similar non-stick properties as PFAS,” he says.  

According to Gu, the benefit of using SDLs for research isn’t just the speed, but their consistency.  

“Every experiment is run and measured the same way, so the data we get back is reliable enough to train the AI models that guide the next round of experiments,” he says.  

The next step is making the SDL fully self-driving, which would mean the robots would be capable of creating PFAS-free coatings on their own. This would close the loop in the design-make-test-analyze cycle, allowing AI to independently run experiments and find the best replacement.  

For Golovin, further advancements to the SDL and to this research could help lead to a responsible solution, and make smartphone use safer for everyone.  

“This work can ideally accelerate the discovery of new materials so that smartphone users in Canada and around the world are no longer exposed to PFAS in this way,” he says.

RAISE-Coating automated abrasion module integrated on the robotic platform. The system uses a custom 3D-printed abrasion tool and automated cleaning station to perform cyclic coating durability tests before interfacial characterization.