image: Fig. 1. Schematic diagram of an on-chip system consisting of multiple functional modules (a) without the cloak and (b) with the designed thermal-electromagnetic cloak, respectively. (a) A central processing unit central processing unit (i.e., thermal sensitive electrical element in the center region) will be affected by the gathered waste heat (indicated by red arrows) from surrounding resistive elements (blue blocks) on chip, which may make the temperature around the processing unit higher than its rated temperature or generate thermal stress/deformation due to the gradient temperature field, and then affect its working efficiency and aggravate the aging. At the same time, the central processing unit will disturb the EM signals (represented by yellow curves) from surrounding radiating components (e.g., the cyan antenna). (b) The designed thermal-electromagnetic cloak (colored orange) is set around the central processing unit in the same on-chip system. In this case, the electromagnetic signals and waste heats can be simultaneously guided around the thermal sensitive central processing unit. As a result, the central processing unit will not be affected by waste heats (or the gradient temperature field from surrounding resistive elements) and not influence radiation pattern of electromagnetic signals from surrounding radiating components. Meanwhile, the waste heat can be effectively collected by the latter cooling/recovery units.
Credit: OES
A new publication from Opto-Electronic Science; DOI 10.29026/oes.2024.230027 discusses simultaneously realizing thermal and electromagnetic cloaking by multi-physical null medium.
Simultaneous management/control of thermal fields and electromagnetic waves is crucial for various electronic systems in many application fields, such as managing heat flow to protect sensitive electronic chip components while providing electromagnetic shielding, as well as optimizing cooling methods and recovering waste heat in electromagnetic/optical devices. This need is particularly pronounced in electronic/photonic on-chip systems with high integration level, where multiple modules are closely integrated within a confined space to provide more functionality, faster processing power, and lower energy consumption. However, it will inevitably bring some new problems, such as simultaneously achieving electromagnetic compatibility and efficient heat dissipation within the limited space of a chip, and simultaneously cloaking electromagnetic waves and temperature fields for on-chip systems. In existing technology, these objectives remain challenging for the following reasons. On one hand, a general theoretical method that can effectively control temperature fields and electromagnetic waves simultaneously is still lacking. On the other hand, there is a shortage of materials that can concurrently control electromagnetic waves and temperature fields.
To solve the current problem of theoretical deficiencies and limited materials for simultaneous control on temperature fields and electromagnetic waves, this work proposes a thermal-electromagnetic null medium which performs as a perfect ‘endoscope’ for electromagnetic waves and thermal fields simultaneously by using transformation optics. Then, a surface-designing method is proposed to effectively control temperature fields and electromagnetic waves simultaneously by following standardized black-box designing steps. Thereafter, staggered copper and expanded polystyrene is utilized to realize the thermal-electromagnetic null medium. As an example, a thermal-electromagnetic on-chip cloak that can work for both electromagnetic waves and thermal fields simultaneously is designed and fabricated, which can protect on-chip sensitive components from the surrounding heat flows while not affecting the electromagnetic radiation patterns from radiating components.
The authors of this article propose a thermal-electromagnetic surface transformation method, which is a novel graphical design frame to simultaneously control of the propagation of electromagnetic waves and heat fluxes, and can be used to design thermal-electromagnetic devices with various functions (e.g., thermal-electromagnetic splitters, benders, converters, multiplexers and cloaks) by standardized black-box designing steps (see Supplementary Movie 1 for more details). At the same time, a thermal-electromagnetic cloak, which can guide both electromagnetic waves and thermal fluxes around the concealed region simultaneously, is proposed and verified by both numerical simulations and experimental measurements. This research pioneers the development of a thermal-electromagnetic invisibility cloak with on-chip applications, presenting a promising solution to both electromagnetic compatibility and heat dissipation challenges in highly integrated on-chip systems (see Supplementary Movie 2 for more details). Notably, the thermal-electromagnetic cloak demonstrates excellent broadband performance for electromagnetic waves, operating effectively across a frequency range from 6GHz to 10GHz.
# # # # # #
The research group has been dedicated to the study of transformation optics, invisibility cloaks, metamaterials/metasurfaces, and the control of multiple physical fields for many years. Currently, there are 3 teachers and 14 graduate students. The group has published more than 70 papers in journals such as Advanced Materials, Physical Review Letter, Laser & Photonics Reviews, Photonics Research, etc., and has been granted more than 20 Chinese invention patents, and has been granted 7 national projects, 2 provincial projects, and 1 joint-laboratory project. Website: https://www.x-mol.com/groups/sun_fei
# # # # # #
Opto-Electronic Science (OES) is a peer-reviewed, open access, interdisciplinary and international journal published by The Institute of Optics and Electronics, Chinese Academy of Sciences as a sister journal of Opto-Electronic Advances (OEA, IF=9.682). OES is dedicated to providing a professional platform to promote academic exchange and accelerate innovation. OES publishes articles, reviews, and letters of the fundamental breakthroughs in basic science of optics and optoelectronics.
# # # # # #
More information: https://www.oejournal.org/oes
Editorial Board: https://www.oejournal.org/oes/editorialboard/list
OES is available on OE journals (https://www.oejournal.org/oes/archive)
Submission of OES may be made using ScholarOne (https://mc03.manuscriptcentral.com/oes)
CN 51-1800/O4
ISSN 2097-0382
Contact Us: oes@ioe.ac.cn
Twitter: @OptoElectronAdv (https://twitter.com/OptoElectronAdv?lang=en)
WeChat: OE_Journal
# # # # # #
Liu YC, Ma XM, Chao K et al. Simultaneously realizing thermal and electromagnetic cloaking by multi-physical null medium. Opto-Electron Sci 3, 230027 (2024). doi: 10.29026/oes.2024.230027
Journal
Opto-Electronic Science