Reducing Energy Loss in Asphalt: A Ph.D. Student’s Research Discoveries 

As wireless charging systems become a reality, rather than an aspiration of the future, ASPIRE researchers are finding ways to continually test and enhance these systems in order to improve their effectiveness. Ph.D. candidate Raquel Sarabia recently published her team’s research addressing the energy efficiency degradation in capacitive wireless power chargers installed in roadways. 

“We found that both asphalt and concrete pavements introduce additional losses in capacitive wireless charging systems,” said Sarabia. “Through system-level analysis, we identified asphalt as a lossy dielectric material and experimentally characterized its electrical properties. Our results showed that allowing high electric fields to propagate through lossy dielectrics leads to significant efficiency degradation.” 

In other words, the asphalt used in the capacitive wireless charging systems was leading to efficiency degradation because of its electrical properties, as asphalt absorbs part of the electric field used for energy transfer. Together with her team at Cornell University, Sarabia discovered a way to reroute the electric field through a more efficient path, lowering the amount of energy lost in the process. 

“To address this, we developed a method to replace the regions of highest electric field intensity with a low-loss dielectric material, effectively mitigating the losses associated with asphalt,” she explained. 

Their research, a part of ASPIRE’s Electrified Roadways project, was presented at the IEEE Energy Conversion Congress and Exposition (ECCE) last October under the title, “Loss Reduction in Pavement-Embedded Multi-MHz Capacitive Wireless Charging Systems for Electric Vehicles”. 

Sarabia herself presented the research and played a critical role in their discoveries. 

“I served as the primary researcher on the project. I led the system design, conducted the experimental work, and performed the analysis to evaluate how asphalt pavement affects the efficiency of capacitive wireless power transfer,” she recalled. “Based on this analysis, I also designed and validated a mitigation strategy to reduce these losses.” 

Sarabia’s Ph.D. Advisor Khurram Afridi, an electrical and computer engineering professor at Cornell University, recognized her efforts to lead the team effort and work towards real-world developments of their prototypes. 

“Raquel’s innovative work on capacitive wireless charging is helping move this potentially lower-cost technology from laboratory prototypes toward pavement-embeddable systems,” said Afridi. “Collaborating with Raquel has been extremely rewarding — her interdisciplinary background in electrical and industrial engineering brings a unique perspective that has allowed us to accelerate the technology’s path toward real-world readiness.” 

In addition to benefiting the field as a whole, Sarabia gained valuable experiences through this unique opportunity to conduct and present her research at ASPIRE. 

“This project was the first research effort I led during my Ph.D. and resulted in my first accepted paper as a doctoral student, making it a strong source of motivation early in my program,” she said. “Professionally, presenting at ECCE allowed me to disseminate my work to the research community, receive feedback, and establish connections with researchers and industry professionals.” 

For the latest news, publications, and research highlights from ASPIRE, visit aspire.usu.edu. 

About ASPIRE: 

ASPIRE, a National Science Foundation Engineering Research Center headquartered at Utah State University, leads groundbreaking research and development to accelerate electrification. With over 400 global collaborators, ASPIRE focuses on creating seamless, affordable electrified transportation systems, accessible for all vehicle classes, along with the public infrastructure needed to support them. By reducing emissions, improving air quality, and fostering economic growth through job creation and workforce training, ASPIRE’s work spans engineering, social science, policy, and business. Partnering with top universities, industry leaders, and community groups, ASPIRE is driving the future of advanced transportation. Learn more at aspire.usu.edu. 

Contacts: 

Steve Pekarek 
Convergent Research Director 
ASPIRE ERC 

Khurram Afridi 
Electrical & Computer Engineering Professor
Cornell University 

Writer: 

Kayleigh Kearsley 
Marketing & Communications Intern 
ASPIRE ERC