As underwater, aerial, and ground unmanned vehicles and wearable power systems continue to play a growing role on our technology horizons, it is critical that the fuel cells necessary to power these systems operate safely, while providing durable and optimal performance. Key to this function are high-performance hydrogen sensors which monitor leakage, energy efficiency, and durability under a wide range of operating temperatures, pressures, and humidity levels.
Currently, palladium-based electrochemical hydrogen sensors are primarily used, however, it is acknowledged they often exhibit low sensitivity, a slow response rate, and mechanical instability. Although graphene-Pd hybrid materials are emerging as a better solution for hydrogen sensing, questions remain regarding their efficacy.
That was the crux of the request for 4-VA funding from Department of Mechanical Engineering’s Pilgyu Kang of George Mason University and Stephen Baek in the University of Virginia’s Department of Mechanical and Aerospace Engineering. Kang saw an important opportunity to explore this new avenue in hydrogen sensing, but also saw the need to integrate Baek’s expertise in scientific machine learning to identify optimal design parameters — including nanoparticle size, distribution, surface coverage, and porosity — that govern the sensor’s sensitivity, response time, and long-term stability.
After months of wide-ranging study, Kang is pleased with the results of the collaboration. By using scientific machine learning, the team can predict how changes in material design affect sensor performance. This helps them quickly test many design possibilities and find the best combinations—something that would take much longer with experiments alone.
“Our research team has made exciting progress in developing advanced materials for next-generation gas sensors. We’ve created and tested nanocomposites made from laser-induced graphene and metal nanoparticles to improve how sensors respond to light and detect gases like hydrogen and methane. The materials we’ve developed show promising photo response behavior, which is a key step toward building compact, highly sensitive sensors for environmental and industrial use,” explains Kang.
Since the initial proposal, Kang credits two added outside collaborators as keys to their success: NASA Goddard Space Flight Center (GSFC) and N5 Sensors — both providing important platforms to explore potential commercialization paths.
Sensor researchers Peter Snapp and Mahmooda Sultana at NASA GSFC collaborated with the research team on the development of a methane gas sensor. They provided expertise in space-relevant sensing technologies and contributed guidance on performance requirements, testing protocols, and potential integration pathways for aerospace applications. Says Kang, “This collaboration strengthens the translational potential of the 4-VA-supported laser-induced graphene nanocomposite sensing platform for real-world and extreme environment use cases.”
N5 Sensors engaged with the research team to offer industry insight into the commercialization potential of the laser-induced graphene-based sensor platform. Their involvement included feedback on sensor integration strategies, performance metrics relevant to the market, and potential pathways for transitioning the research from lab-scale prototypes to scalable, deployable systems.
The George Mason University component of the team included Peter Cho, from the Department of Mechanical Engineering, who volunteered his time to evaluate the hydrogen sensing performance of the developed materials and advising on sensors relevant to fuel cell applications.
Kang credits four undergraduate students from the Department of Mechanical Engineering who made significant contributions to the project and benefited from rich experiential opportunities:
- Philip Acatrinei shared key material and device integration techniques—particularly in the use of laser-induced graphene and nanocomposite fabrication for advanced sensor platforms.
- Graham Harper studied laser-induced graphene and nanocomposite materials for optoelectronic sensing applications.
- Noemi Lily Umanzor helped to validate the broader versatility and cross-disciplinary potential of the materials and manufacturing approaches developed in the project.
- Diego Enrique Colmenarez performed experimental tasks involving the laser manufacturing and characterization of graphene-based nanocomposites. For his work, Colmenarez received the “Outstanding Project Award” at the College of Engineering and Computing Undergraduate Research Celebration. He also presented the subject at the American Society of Mechanical Engineers Undergraduate Research Symposium on Dynamics, Vibration & Acoustics.
“Our research team has made exciting progress in developing advanced materials for next-generation gas sensors. We’ve created and tested nanocomposites made from laser-induced graphene and metal nanoparticles to improve how sensors respond to light and detect gases like hydrogen and methane. The materials we’ve developed show promising photo response behavior, which is a key step toward building compact, highly sensitive sensors for environmental and industrial use,” explains Kang.
The team has already had two published papers on the project, in the Journal of Materials Chemistry C and Advanced Science. However, Kang sees the 4-VA project as a launching pad for much more; noting, “The funding provided the essential support needed to launch a high-risk, high-reward interdisciplinary research project that might not have been possible through traditional funding channels alone. It enabled a new and productive collaboration between GMU and UVA, bringing together complementary expertise in laser manufacturing and AI-driven material design. The funding also created valuable hands-on research opportunities for undergraduate students. Beyond advancing the technical goals, the support from 4-VA has helped position our team for larger external funding, fostered long-term partnerships, and demonstrated how collaborative, cross-institutional work can drive real innovation.”