NEWS | May 6, 2021

NRL Designs Faster, More Energy Efficient Unpiloted Underwater Vehicles

By Nicholas E. M. Pasquini, U.S. Naval Research Laboratory Corporate Communications

Nicole Xu, Ph.D., a U.S. Naval Research Laboratory (NRL) Postdoctoral Research Associate from the Laboratories for Computational Physics & Fluid Dynamics designs faster and more energy efficient underwater vehicles using bioinspired shark skin-like surfaces.

“Shark skin comprises arrays of teeth-like denticle structures, which contribute to fast and stealthy swimming by turbulent drag reduction,” Xu said.  She began her NRL postdoctoral associateship in January 2021.

“Xu has demonstrated extraordinary motivation and initiative, as well as technical expertise in the area of unpiloted systems research,” said Jason Geder, an NRL aerospace engineer who is Xu’s mentor.

Xu’s goal is to test these bioinspired surfaces on hydrofoils in flow channels before implementing the skins onto unpiloted underwater vehicles (UUV), such as the NRL-developed WANDA UUV and other traditional underwater vehicles.  

“Because the denticles possess complicated microstructures, I am currently testing 3D printing capabilities and designing the foils to conduct our initial experiments in a water tunnel,” Xu said. 

Equality in the Classroom and Workplace

“The rhetoric has palpably changed for women in Science, Technology, Engineering and Math (STEM),” Xu said.  “From how women can assimilate into male-dominated fields to how male-dominated fields can be more inclusive and seek underrepresented groups.”

In high school and college, Xu was advised to never show emotion or lack of strength as a woman in engineering, for fear that male engineers wouldn’t take her, or other female engineers, seriously. 

“In graduate school, I began to see the discourse shifting,” Xu said.  “Faculty of all genders spoke candidly about their struggles in research, and emphasized that emotions are humanizing, not demonizing.  I also worked in a mechanical engineering laboratory with primarily female graduate students, which I did not consciously view as noteworthy until someone else pointed it out.  It was just normal to me.”

Xu was warned that the more education she received and the more years of experience at work, the more she would see injustices that would grind her down.  

“While I still see both deliberate and unintentional sexist actions in the world, I also see positive changes,” Xu said. “I have been supported by allies in positions of power, who have defended me and asked to hear my opinions.”

Xu remembers the support she received and advocates for the next person. “We all stand on the shoulders of giants, and we pave the way for future giants,” she said. 

Starting a New Job during a Pandemic

“Starting a postdoctoral position during the pandemic is challenging,” Geder said.  “Dr. Xu has integrated with the NRL community seamlessly and I look forward to working together as she continues her research and integrates her results into other ongoing efforts at NRL and across the unpiloted systems research community.” 

Xu admitted it feels strange to start a position in a primarily virtual environment, but this is offset by the accessibility of her principal investigators, mentors, and colleagues and their willingness to help her acclimate – from offering detailed trainings to informal tidbits about life around the laboratory. 

“I strongly believe that a good work environment is paramount, and from my experiences here so far, I feel well supported with a balance of guidance and creative freedom,” Xu said.

Xu earned a bachelor’s of science and engineering from the University of Pennsylvania in 2014, a master’s of science at the California Institute of Technology in 2015, and a doctoral research degree from Stanford University in 2020.


About the U.S. Naval Research Laboratory 

NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL is located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, California, and employs approximately 2,500 civilian scientists, engineers and support personnel.

For more information, contact NRL Corporate Communications at (202) 480-3746 or nrlpao@nrl.navy.mil.