As the use of underwater, aerial, and unmanned ground vehicles continues to grow, it is critical that the fuel cells necessary to power these systems operate safely, while providing durable and optimal performance. High-performance hydrogen sensors, which monitor leakage, energy efficiency, and durability under a wide range of operating conditions, are key to this function.
Currently, palladium-based electrochemical hydrogen sensors are primarily used; however, they often exhibit low sensitivity, a slow response rate, and mechanical instability. Hybrid materials are emerging as a better solution, but questions remain regarding their efficacy.
That was the crux of the request for 4-VA funding from George Mason University’s Pilgyu Kang and Stephen Baek of the University of Virginia. Kang saw an 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. 4-VA funding is designed to support these kinds of collaborations.
Kang, an assistant professor in the Department of Mechanical Engineering, is pleased with the results. After months of wide-ranging study, the team can now predict with the help of machine learning how changes in material design affect sensor performance. This helps the team 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,” said Kang, who has a lab on George Mason’s Science and Technology Campus. “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.”
Since the initial proposal, Kang has added outside collaborators NASA Goddard Space Flight Center (GSFC) and N5 Sensors, both providing important platforms to explore potential commercialization paths.
NASA GSFC researchers Peter Snapp and Mahmooda Sultana collaborated with the 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.
“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,” said Kang.
N5 Sensors offered 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.
Peter Cho of the Department of Mechanical Engineering also worked with the team, volunteering his time to evaluate the hydrogen sensing performance of the developed materials and providing advice on sensors relevant to fuel cell applications.
Kang said the 4-VA funding also helped create valuable hands-on research opportunities for undergraduates. He credits four mechanical engineering majors who made significant contributions to the project:
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Philip Acatrinei shared key material and device integration techniques—particularly in the use of laser-induced graphene and nanocomposite fabrication for advanced sensor platforms.
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Graham Harper studied laser-induced graphene and nanocomposite materials for optoelectronic sensing applications.
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Noemi Lily Umanzor helped to validate the broader versatility and cross-disciplinary potential of the materials and manufacturing approaches developed in the project.
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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 on the subject at the American Society of Mechanical Engineers Undergraduate Research Symposium on Dynamics, Vibration and Acoustics.
The team has already had two published papers on the project in the Journal of Materials Chemistry C and Advanced Science, but Kang sees the 4-VA project as a launching pad for much more.
“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,” he said. “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.”