Dongsheng Chen Defends Dissertation on Jet-Propelled Soft Robotics

Dongsheng Chen has successfully defended his doctoral dissertation, “Design, Performance Analysis and Motion Control of a Jet-Propelled Soft Robotics Platform,” under the supervision of Cynthia Sung, Associate Professor in Mechanical Engineering and Applied Mechanics (MEAM). His research advances the control of soft underwater robots, bringing scientists closer to robotic systems that can safely and efficiently navigate complex aquatic environments.

Unlike conventional rigid robots, soft robots are built from compliant materials that can bend and deform, making them well suited for navigating delicate or unpredictable environments. But controlling these flexible machines, especially underwater, remains a significant challenge. In his dissertation, Chen developed motion control strategies for a jet-propelled soft robotic platform, combining modeling, performance analysis and control algorithms to enable more reliable underwater locomotion.

His work addresses one of the field’s most difficult problems: controlling robots whose soft bodies constantly deform as they move through water. By developing a framework that allows these robots to navigate more effectively, his research expands the possibilities for soft robotic systems in applications ranging from environmental monitoring to underwater exploration.

Chen began his Ph.D. at Penn in 2020, with his first year and qualifying exams taking place entirely online during the COVID-19 pandemic. Despite the unusual start, he found a strong community within MEAM and across Penn.

“I built strong friendships within my cohort and the lab, explored various projects to identify my true research passions and had the fulfilling experience of mentoring students,” he says. In addition to his research, Chen served as a teaching assistant for both undergraduate and graduate courses and joined the committee for the General Robotics, Automation, Sensing and Perception (GRASP) SFI Seminar, connecting with researchers across disciplines. “It has been quite a journey, and I am very glad to finally be wrapping it up.”

One moment stands out above all the others. After years of breaking an exceptionally difficult research problem into smaller pieces, it was finally time to test the complete motion controller on the physical robot.

“I honestly didn’t know if it was going to succeed because I had to make so many assumptions and simplifications,” he recalls. “I remember standing in the water tank, watching the PC screen jump back to the motion capture interface, which meant the controller had converged. I literally yelled, ‘Holy cow, it actually worked!'”

Looking ahead, Chen is pursuing industry opportunities in robotics, where he hopes to apply his research experience to developing impactful real-world technologies.

For students considering a Ph.D. in MEAM, his advice is simple: “Chase your passion.” He encourages future researchers to explore broadly before committing to a research area.

“A Ph.D. is a long commitment that will shape your career, so find a research area that genuinely excites you,” he says. “Don’t worry about switching fields or not knowing everything right away, you will have plenty of time to learn the necessary skills. Ultimately, a Ph.D. is about you. It is your opportunity to build a future you genuinely believe in and are excited about.”

Chen extends his deepest gratitude to his advisor, Cynthia Sung.

“Early on, I knew very little about research and how to behave professionally and made plenty of rookie mistakes, but she patiently guided me through those mistakes,” he says. “Looking back now, I truly appreciate the moments when she pointed out my mistakes and taught me the right way to do things. Thanks to her training, I have grown into an independent and professional researcher.”