Researchers at the University of Houston have proposed a new approach to thermal management that could help extend battery life and improve reliability in electronics, vehicles, and space systems. The work, led by Bo Zhao from the Cullen College of Engineering and carried out with doctoral researcher Sina Jafari Ghalekohneh, explores how heat can be directed to flow preferentially in one direction, an effect known as thermal rectification.
Jafari Ghalekohneh, S., & Zhao, B. (2026). Asymmetric thermal conductivity mediated by nonreciprocal polaritons. Physical Review B, 113(4), L041403. https://doi.org/10.1103/pplf-ytqm
Thermal management has become a limiting factor for many modern technologies. Batteries, high-performance processors, and power electronics all generate heat that must be removed efficiently to prevent degradation or failure. Conventional materials allow heat to move freely in multiple directions, which makes precise control difficult, especially in compact or sealed systems. The Houston team’s research suggests that it may be possible to guide radiative heat in a more controlled way, similar to how an electrical diode directs current.
Bo Zhao from University of Houston stated,
“Basically, you have a hot side, a cold side and something in the middlle. If you look at a triangle, you want to have heat to transport counterclockwise from surface one to surface two, then surface two to surface three—you can’t have it go from two to one. It essentially creates a heat loop.”
The proposed “thermal diode” relies on nonreciprocal materials, specifically semiconductor structures exposed to magnetic fields. Under these conditions, the microscopic behavior of energy carriers changes, allowing heat radiation to pass in one direction while being strongly suppressed in the opposite direction. According to the researchers, this directional control could allow excess heat to leave a device while limiting unwanted heat from entering, a balance that is particularly important for batteries operating in hot environments.
The study, focuses on radiative heat transfer, which becomes dominant when convection is limited or absent. This makes the concept especially relevant for applications such as satellites, where electronics are exposed to intense solar radiation but cannot rely on air for cooling. By allowing internal heat to escape while blocking incoming thermal radiation, the researchers suggest that satellite systems could operate more consistently and with reduced thermal stress.
In related work published in Physical Review B, the team extends the same principles to conductive heat transfer. This companion study demonstrates theoretically that nonreciprocal effects can also produce asymmetric thermal conductivity, meaning heat conducted through a solid could preferentially move in one direction. If realized experimentally, this could have implications for managing heat in microchips, power electronics, and battery packs, where conduction plays a central role.
Beyond diodes, the researchers also describe the concept of a thermal circulator. In this configuration, heat is guided to move in a closed loop among multiple surfaces rather than simply from hot to cold. Such a mechanism could enable more advanced thermal architectures, where heat is redistributed within a system to stabilize temperature differences without relying on bulky cooling hardware.
While the current results are theoretical, similar ideas have been explored in recent studies from other research groups investigating phononic and photonic thermal control. Together, these efforts point to a broader trend toward treating heat flow as something that can be engineered with the same level of intent as electrical or optical signals. Experimental validation remains a key next step, and Zhao’s group has indicated that prototype platforms are a priority for future work.
If successfully demonstrated, directional heat control could have wide-ranging effects. Consumer electronics might see longer battery lifetimes and improved performance under heavy use. Electric vehicles could benefit from more stable battery temperatures, reducing degradation over time. Data centers and emerging AI hardware, which face increasing thermal demands, could also gain new tools for managing heat more efficiently.
The research highlights how fundamental advances in thermal physics can translate into practical engineering solutions. By rethinking how heat moves at the material level, the study offers a possible path toward more efficient and durable energy storage and electronic systems, at a time when thermal management is becoming as critical as power delivery itself.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
