The latest from Jacobs School of Engineering professors and alumni pioneering the industry.
We spoke with Patrick Mercier, professor of Electrical and Computer Engineering and co-director of the Center for Wearable Sensors (CWS), and Joseph Wang, professor of Nanoengineering and co-director of CWS.
Why should we be excited about wearables?

PM: Wearables are starting to offer interesting insights into our daily behavior and our health. Today’s Apple Watches and Fitbits can track things like your activities and heart rate, and can even provide estimates on your exercise potential, but these are just the tip of the iceberg. The technologies we’re developing at CWS will give us much more interesting and actionable information that will complement what’s available to provide a richer set of data to help people live better lives and figure out what’s working for them in terms of exercise, nutrition, medication, and clinical treatment.
Who would benefit most from advances in wearable technology?

JW: Wearables that provide continuous monitoring would benefit people who are managing chronic diseases, such as diabetes and heart disease. Ideally the monitoring would be as non-invasive as possible. In the case of people with diabetes, continuous glucose monitors that do not require the user to draw a blood sample multiple times a day would be a game changer. At CWS, we’re moving forward technologies that can continuously monitor multiple parameters, which could help even more people managing different types of conditions.
What are the challenges in making wearables part of everyday life?
JW: One of our main technical challenges is accuracy—can wearables get the same information that we normally get from the blood from the surface of the skin instead? They also need to be comfortable to wear, so making them soft, flexible, and stretchable without sacrificing performance is a challenge from the materials science standpoint. Biocompatibility is another challenge; they have to be non-toxic and stable over the long term so people can actually use them reliably 24/7.
What will wearables look like in the future?
PM: We’ll be moving from big, bulky devices to ones that are sleek and integrated into everyday items. This is where the concept of what we call “unawearables” comes into play: these are next-generation wearable devices that are so small and unobtrusive that users are virtually unaware that they’re wearing their wearables. And if we can integrate these functionalities into things people already wear, like underwear, socks, belts, rings, or glasses, then users can get access to rich information without having to change their behavior.
What is different about the way CWS is engineering the next generation of wearables?
JW: Wearables are not just about the sensors. We’re working toward a complete wearable platform. Our faculty teams are experts in advanced biosensing technologies, flexible and stretchable electronics, ultra-low power circuits, bioenergy harvesting, machine learning, data analytics, data communication, and data security. We also collaborate with researchers in the UC San Diego School of Medicine too, which allows us to better tailor these technologies for clinical use.
PM: Such a holistic view brings extra value to the table because a lot of our challenges are linked. You could build the world’s best biosensor, but without a low-power electronic system to run it, then you’re limiting your technology to something that needs to be plugged into a wall. We are trying to solve all these problems together. Our cross-collaborations are key in enabling us to develop the next generation of wearable devices.

Joshua Windmiller ’07, MS ’09, PhD ’12, co-founded the company Biolinq with Jared Tangney, ’09, MS ’12, PhD ’14 to create what he calls, “the front end for digital health.” Their first product is a skin-applied patch for continuous glucose monitoring for individuals with diabetes, but the ultimate goal is to advance the frontier of non-invasive technology and use its clinical-grade information on metabolism to help folks live happier, healthier, and more productive lives.
What was your experience at UC San Diego and the Center for Wearable Sensors?
The most extraordinary opportunity in the lab was the ability to conduct highly interdisciplinary research largely focused on grand challenges. It was a dynamic and collaborative environment as well; we were encouraged to try new things and it was okay to fail, too. It was great to be at the forefront of a lot of the activities that have culminated into today’s market of wearable sensors. Joe Wang and Patrick Mercier had a lot of faith in what I was doing in my research, as well as in the field of wearable technology in general; their passion is contagious and was a main factor for me to enter such a burgeoning area of research.
What should we know about wearable sensors?
Sensors are a way to de-mystify the world around us, to make sense of our surroundings. They convert some sort of physical or chemical quantity into digital information that we can make use of. In the future, what we’ll see are sensors that can provide individuals with a copious amount of information pertaining to health surroundings, at a very immediate rate. Having this increased accessibility to information will aid in the decisions we make, so as sensors get smarter, we’ll get a lot smarter too.

Rajan Kumar, MS ’16, PhD ’19 started his company Ateios with fellow Tritons Carlos Munoz ’16, MS ’20 and Rushabh Shah, MS ’19, to solve the battery issue in flexible electronics. Using a custom-made rapid manufacturing process, they aim to do away with bulky and rigid batteries as we know them and instead shape batteries around products, rather than the other way around.
How did you enter the field of wearable batteries?
I had done a lot of work on medical sensors, and I knew that to really enable the potential of wearables, we have to look at everything around it: the software, how it will be worn, how it looks, and of course, the power source. That was the biggest problem I saw—as my colleagues were developing these ultra-thin and flexible devices, the battery was still this ugly thing ruining all the innovation. They’d have to hide it away under garments when they published results. It was a problem I was very excited to solve.
What should we know about wearable batteries?
Batteries can be thought of as the missing link that will make advances in wearable sensors truly integrated into our lives. Any electronic that is going to be part of a textile will need that special battery—flexible and stretchable just like the sensor itself. As for our vision—imagine a person putting on a track jacket or athletic shirt. They go run or workout for an hour and it measures all sorts of biomarkers with built-in sensors. Then they go home and shower, the shirt goes into a hamper that wirelessly charges it as it sits there waiting for the wash. It’s just like a regular textile, but it moves and feels like normal, which is essential if we are to truly adopt these technologies