Academic Background

With the rapid development of artificial intelligence (AI), the role of electronic devices in modern life has become increasingly important. However, these devices generate a significant amount of heat during operation, and if not managed effectively, this can lead to performance degradation, shortened lifespan, and even system failure. Therefore, thermal management has become one of the key challenges for the future development of electronic devices. Although traditional cooling technologies are effective, they struggle to meet the demands as the power density of devices increases. In particular, the “Dark Silicon Problem”—where not all transistors in a chip can operate simultaneously due to thermal constraints—further exacerbates the complexity of thermal management.

To address this challenge, a research team from Shanghai Jiao Tong University and Nanyang Technological University published a paper titled “Passive Thermal Management of Electronic Devices” in the journal Device. The paper proposes a comprehensive framework detailing the role of various cooling technologies in electronic devices, with a special focus on passive cooling technologies that do not rely on additional power consumption.

Source of the Paper

This paper was co-authored by Haoran Liu, Chun Yang, and Ruzhu Wang and was published in Device in 2024. Liu and Wang are from the Institute of Refrigeration and Cryogenics at Shanghai Jiao Tong University, while Yang is from the School of Mechanical and Aerospace Engineering at Nanyang Technological University in Singapore. The corresponding author of the paper is Ruzhu Wang, whose research focuses on solar refrigeration and thermal management.

Main Content of the Paper

1. Classification and Evaluation of Passive Cooling Technologies

The paper first provides a detailed classification of passive cooling technologies, including software control algorithms, sorption-based evaporative cooling, sky radiative cooling, and phase change materials (PCMs). These technologies effectively reduce the temperature of electronic devices without additional power consumption, leveraging different physical principles. For example, sky radiative cooling utilizes the emission of infrared radiation to the cold universe, while sorption-based evaporative cooling removes heat through the adsorption and release of moisture by materials.

Supporting Evidence

• The principles and practical applications of sky radiative cooling (e.g., cooling of LED lamps and foldable displays).
• Experimental results of sorption-based evaporative cooling, demonstrating its cooling effects in smartphones and base stations.

2. Application of Software Control Algorithms

The paper also explores the optimization of thermal management in electronic devices through software control algorithms. These algorithms dynamically adjust device operating parameters to maximize the utilization of existing cooling capacity, thereby improving device performance without altering hardware design. For instance, model predictive control (MPC) algorithms determine control variables at each time step by solving optimization problems online, ensuring the device operates within thermal constraints.

Supporting Evidence

• Applications of MPC algorithms in mobile electronic devices and multi-core processors.
• Control effects of machine learning (ML) algorithms in fan-cooled platforms and multi-core processors.

3. Combined Hardware and Software Thermal Management

The paper emphasizes that relying solely on hardware or software thermal management solutions has limitations. Only by combining both can optimal performance of electronic devices be achieved. For example, heat sinks and heat pipes in hardware design can effectively conduct heat, while software control algorithms can optimize device operating modes to prevent overheating.

Supporting Theories

• Classification and evaluation metrics of hardware technologies such as heat conduction, closed-loop cooling, and open-loop cooling.
• Synergistic effects of software control algorithms and hardware design, highlighting the necessity of integrated solutions.

4. Future Research Directions

The paper also points out future research directions for passive cooling technologies. For example, sorption-based evaporative cooling has discontinuous cooling power output, and designing materials to balance device load and adsorption capacity is an important topic. Additionally, combining sorption-based evaporative cooling with sky radiative cooling may further enhance cooling effectiveness.

Supporting Perspectives

• Design and optimization of adsorption materials, such as metal-organic frameworks (MOFs) and salt-based composite materials.
• Innovations in sky radiative cooling materials, such as the development of angle-selective emitters.

Significance and Value of the Paper

This paper provides a comprehensive framework for the thermal management of electronic devices, offering many innovative insights, particularly in passive cooling technologies. By combining software control algorithms with hardware design, the paper presents new ideas for the thermal management of future electronic devices. Furthermore, the paper explores the potential applications of these technologies in other fields, such as batteries, thereby expanding their practical value.

Highlights Summary

1. Comprehensive Framework: The paper proposes an all-encompassing thermal management framework that covers both hardware and software technologies.
2. Innovative Technologies: Detailed introduction of emerging passive cooling technologies such as sorption-based evaporative cooling and sky radiative cooling.
3. Cross-Disciplinary Applications: Exploration of the application prospects of passive cooling technologies in fields like batteries, showcasing their broad practical value.
4. Future Directions: Clear directions for future research, particularly in material design and system integration.

Through this paper, the research team not only provides new solutions for the thermal management of electronic devices but also offers valuable references for the future development of technology.