Anxiety can be overwhelming, especially in the kind of turbulent times we’ve all been enduring these past few years. But, thanks to new technology from scientist Chuanzhen Zhao M.S. ’17, Ph.D. ’20, we may soon be able to measure in any precise moment exactly how stressed we are — and take the proportional steps to deal with it. 

“I got an email from a single mom with two kids,” Zhao recalls. “She was quite stressed out, and she said, ‘I think the technology you guys are developing can help a lot, and even save people’s lives.’” 

Such cries for help motivated Zhao to keep the focus of his UCLA Ph.D. thesis on wrist patches, known as biosensors, that measure stress hormones in perspiration. His first version was like a watch; the latest iteration is more like a nicotine patch worn on the wrist. 

A key biomarker for mental health monitoring is cortisol, a known stress hormone. But measuring cortisol levels so that people can, in real time, read the danger signs and then take contrary action — a cup of tea, a moment of meditation, a call to a friend — has always been a challenge.

Until now. Unlike traditional tests, which require invasive methods such as fingerstick blood tests, Zhao’s sensors measure biochemical markers by “tasting” everyday sweat. The secret lies in the chemistry: Zhao collaborated with a team of eminent professors and graduate student researchers from UCLA and Columbia University to develop an artificial DNA strand capable of binding with cortisol. Zhao’s groundbreaking work not only earned him a spot on the Forbes 30 Under 30 science list in 2022, it also won him the Nanotechnology Council’s Best PhD Thesis Award.

But for Zhao, such accolades pale in comparison to the real ways in which his sensors aid people dealing with stress. Now a postdoctoral scholar at Stanford University, Zhao is continuing his development of wearable sensors; his team is currently working on “skin-inspired electronics” that work as a polymer film that can be stretched and placed on the skin to monitor mental health and other diseases. The more we learn about the role of biochemical markers in anxiety and depression, the more we can imagine what kinds of stories our skin can tell us.

“We wanted to develop something,” Zhao says, “to really benefit the whole community.”

Read more from UCLA Magazine’s Spring 2024 issue.