Marking a significant advancement for small- and micro-scale energy systems, researchers led by Professor Guoyao Yu from the Chinese Academy of Sciences have developed a novel hybrid thermoacoustic electric generator (HTAEG) featuring a post-positioned gas spring. This innovation promises ultra-high output power and remarkable efficiency, particularly suited for space nuclear power applications. The breakthrough, achieved in collaboration with Dr. Yanyan Chen, Mr Yuanhang Chen,  Dr. Jing Luo, Dr. Yanlei Sun, Professor Ercang Luo from the Chinese Academy of Sciences, and Dr. Shunmin Zhu from Durham University, marks a major milestone in thermoacoustic technology. Their findings were published in the peer-reviewed journal Cell Reports Physical Science.

Professor Yu’s team proposed and tested a hybrid thermoacoustic electric generator with a gas spring placed after the displacer. This strategic positioning was crucial in overcoming the limitations of conventional designs, which typically struggle to maintain high power levels and efficiency simultaneously. The new design achieved exceptional electric power and high efficiency, demonstrating the potential for significant energy output.

Thermoacoustic electric generators (TAEGs) convert thermal energy into acoustic energy, which is then transformed into electricity. The hybrid version, which incorporates a solid mass to tune the internal acoustic field, offers superior power density and thermal-to-electrical efficiency. However, scaling up to higher power levels has been a formidable challenge due to limitations in spring force mechanisms.

The novel approach of using a post-positioned gas spring addresses these challenges effectively. Unlike traditional planar springs, gas springs provide higher stiffness levels, crucial for supporting the increased mass and size of the displacer in high-capacity HTAEGs. Additionally, this design minimizes dead volume and flow friction loss, enhancing overall system efficiency.

Professor Yu explained the significance of this innovation: “The gas-spring-post-positioned design significantly reduces the structural complexity and flow friction loss in the compression space, leading to higher efficiency and power output. This design holds enormous potential for various applications, especially in space power systems where reliability and efficiency are paramount.”

Experimental evaluations confirmed the prototype’s exceptional performance. The prototype achieved a maximum electric power output and high efficiency at various input heating powers, demonstrating the versatility and robustness of the design.

These results represent the highest reported power level for a single-piston HTAEG and indicate significant potential for future developments. The researchers plan to further explore the operational characteristics of this design, including the possibility of developing an opposing system with two such HTAEGs to mitigate system vibrations.

Professor Yu and colleagues’ innovative approach not only advances the field of thermoacoustic technology but also opens new avenues for its application in space and other demanding environments. As the global demand for efficient and reliable power solutions continues to grow, this breakthrough offers a promising solution to meet these needs.

Journal Reference

Chen, Yuanhang, Guoyao Yu, Yanyan Chen, Shunmin Zhu, Jing Luo, Yanlei Sun, and Ercang Luo. “Post-positioned gas spring enables ultra-high output power of hybrid thermoacoustic electric generators.” Cell Reports Physical Science, 2024. DOI:

About The Authors

Yuanhang Chen obtained his Bachelor degree from Beijing Institute of Technology in 2020. He is currently a Ph.D. candidate at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. His research focuses on thermoacoustic and Stirling systems, especially the hybrid thermoacoustic electric generator. Yuanhang Chen (

Guoyao Yu obtained his Bachelor’s degree from Zhejiang University in 2003 and completed his Ph.D. degree at the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences in 2008. Currently, he is a full professor at the Technical Institute of Physics and Chemistry. His research primarily focuses on thermoacoustic and Stirling systems, encompassing refrigeration as well as electric power generation based on advanced thermoacoustic and Stirling technologies. Guoyao Yu (

Yanyan Chen received her Bachelor’s degree from Xi’an Jiaotong University in 2003 and her Ph.D. degree from the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences in 2008. She specializes in complex fluid and heat transfer analysis, engineering design, and applications such as thermoacoustic heat engines, bi-directional turbines driven by thermoacoustics, high-power free-piston Stirling technology, and the development of a low-temperature thermostat for temperature referencing. Yanyan Chen (

Dr Shunmin Zhu is a Marie Curie Fellow at the Department of Engineering, Durham University. He is also a Fellow of Durham Energy Institute. Dr Zhu received his Ph.D. degree from the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences in 2020. His research interests include free-piston internal/external combustion and free-piston Stirling engines, thermoacoustic power generation technologies, and hybrid renewable energy systems. Shunmin Zhu (