Michael Ryan Filgas’s Summer 2025 Internship at SUSTECH, Shenzhen, China
Read below about Michael Filgas’s Summer 2025 journey as a research intern in Professor Chuanfei Guo’s biopolymers lab and Professor Hong Chen’s energy storage lab at SUSTECH in Shenzhen, China.
When I first arrived in Shenzhen before beginning my research at SUSTECH, I was amazed by the kindness of random individuals. If I were lost and confused in a train station, people would stop, pull out their phones to translate, and ask if I needed help. That same kindness carried over into the labs where snacks would be left on my desk, and the whole group often invited me to dinner. Some of the guys even offered to train me in the gym for the summer, and thanks to them, I built a routine that I’ll keep following at home.
This warm sense of community made my transition into research even more welcoming. I started in Professor Guo’s biopolymers lab, where the focus was on wearable sensors made from conductive hydrogels—a type of water-based, electrically conductive gel material. At first, I spent time reading and was paired with graduate students to make hydrogels and run tensile (stretching) and resistivity (electrical resistance) tests. Together, we built pressure-sensing insoles shaped like human feet using flexible films and electrodes. I also gained meaningful hands-on experience with fabrication tools, including laser cutters, which use focused light to cut materials, and plasma bonding equipment, which uses ionized gas to join surfaces. Outside of the lab, we’d often go out as a group to nearby restaurants, trying dishes from each member’s province as the weeks went by.
The camaraderie I found in the lab extended beyond research. During this time, I also traveled around Shenzhen with fellow GLOBE students. We explored malls, science museums, and parks, all thanks to how convenient and cheap the public transit system is. I must have gone to the park near the Civic Center five times. Campus’s beauty was on full showcase: lychee trees, ducks wandering around, black swans, and koi swimming under the main bridge. I walked across campus every day, choosing not to take the bus so I could soak it all in.
After gaining initial lab experience, I transitioned to Professor Chen’s lab, where I studied special hydrogels—water-based gels that conduct electricity—used in zinc-ion batteries. These act as a middle ground between liquid electrolytes (conductive solutions) and solid-state electrolytes (rigid, conductive materials), making batteries safer, more stable, and more compact. To familiarize myself with the process, I started with readings and learned how to make hydrogels using an ultrasonic machine for homogeneity (even mixing), or just a mortar and pestle to mix additives. I then tested the gels by stretching them, measuring conductivity (the ability to conduct electricity), and helping assemble coin batteries (small, disc-shaped batteries). This work marked my first deep dive into energy storage research, and it was incredibly exciting to see how small changes in material properties could make such a big difference in performance.
As my time in China drew to a close, my parents visited me, and Professor Guo invited us to a farewell lunch with his graduate students. As we said our goodbyes, he told me to let him know if I ever come back to China so he could host me again. After that, I spent the rest of my time showing my parents around Shenzhen, taking them to the places I had lived and explored for the past two months.
Reflecting on the entire journey, this summer was one of the most rewarding experiences I’ve ever had. I grew as a researcher by working on hydrogels for both bioelectronics and batteries, and as a person, thanks to the kindness and generosity of the people I met. Shenzhen has become a place that feels like home, and I know I’ll be returning someday.
Written by: Michael Ryan Filgas
UC Berkeley Undergraduate Materials Science & Engineering