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With the increased level of integration and miniaturization of modern electronics, high-power density electronics require efficient heat dissipation per unit area. To improve the heat dissipation capability of high-power electronic systems, advanced thermal interface materials (TIMs) with high thermal conductivity and low interfacial thermal resistance are urgently needed in the structural design of advanced electronics. Metal-, carbon- and polymer-based TIMs can reach high thermal conductivity and are promising for heat dissipation in high-power electronics. This review article introduces the heat dissipation models, classification, performances and fabrication methods of advanced TIMs, and provides a summary of the recent research status and developing trends of micro- and nanoscale TIMs used for heat dissipation in high-power electronics. [ABSTRACT FROM AUTHOR]

With the refinement and miniaturization of integrated electronic devices, the requirements for stable operating temperature and antielectromagnetic interference are increasingly high. However, most of the current materials necessitate to develop the intelligent self‐adaptive regulation in response to external field stimuli to gratify the stipulations of different operating environments. Herein, cuttlefish‐inspired smart liquid metal based‐liquid crystal elastomer (LGN‐LCE) dual‐functional material enabling self‐adaptive electromagnetic wave interference shielding and thermal management is presented. Liquid crystal elastomer matrix endows the LGN‐LCE dynamic self‐morphing properties under thermal activation, which leads to the liquid metal network with tunable thermal/electrical conduction. The thermal conductivity of LGN‐LCE can be increased to 10.3 W m−1 K−1 with the rise of surrounding temperature, while the electrical conductivity of LGN‐LCE can be enhanced to 4.3 × 105 S m−1. Such promoted electrical conductivity helps strengthen electromagnetic interference (EMI) shielding performance of LGN‐LCE, and the minimum EMI shielding effectiveness of LGN‐LCE can be improved from 48 to 62 dB within the X‐band. This work may not only pave a new way to rationally design a self‐adaptive EMI shielding and thermal management systems, but also show good prospects for practical applications, including thermal management materials, EMI materials, flexible electronic materials, smart materials, artificial intelligence systems, biomedical, and aerospace applications. [ABSTRACT FROM AUTHOR]

This paper reports the generation of 3D thermal and electrical conductive graphene network in gallium‐based liquid metal (LM) via a simple one‐step ball‐milling approach. In this work, 2D graphene nanoplates and their derivatives were employed to construct 3D thermal and electrical conductive filler networks. It is demonstrated that the obtained composite exhibits the highest 3D thermal conductivity (44.6 W m−1 K−1) among the other gallium‐based LM composites with 2D inorganic nanofillers and distinguished electrical conductivity (8.3 S µm−1) among gallium‐based LM composites at present. The enhanced thermal conductivity and wettability of gallium‐based composite lead to its beneficial usage as thermal interface materials with exquisite texture for LED chip heat dissipation. The electrochemical and magnetic experiments confirm that these LM‐based composites can also be controlled under external electrical or magnetic field, which potentially can help extend their application in external field‐driven systems. The findings of this work offer new insight in designing LM‐based composites with enhanced thermal, electrical, and magnetic properties for a wide range of applications, including thermal management systems, 3D printing, flexible conductors, soft robotic systems, and wearable energy technologies. [ABSTRACT FROM AUTHOR]

We report the development of transparent high-thermal-conductivity nanofluids for enhanced flow cooling of solid-state laser crystal rods. The transparent nanofluids were prepared by dispersing citrate-stabilized Au nanoparticles in water and strictly controlling the particle size and loading. The Au nanofluids have shown stable dispersion, high optical transparency at the excitation wavelength of the YAG solid-state laser (808 nm), and 50% increase of thermal conductivity. Experimental measurement and theoretical simulation of circulating flow cooling show that the heat dissipation capacity of the lasering rod could be increased by more than 20% by using the Au nanofluids to replace pure water coolant.Abbreviations: Au: Gold; NP: Nanoparticle; Au NP: Gold nanoparticle; SEM: Scanning electron microscopy [ABSTRACT FROM AUTHOR]

• Observation of enhanced photothermal performance of BNNS-P3HT composite film. • Increased in-plane thermal conductivity of BNNS-P3HT composite film by hot-pressing. • Cytotoxicity test of such composite film shows prospect in photothermal biosystems. This paper presents a study on the impact of π-π stacking interaction on the thermal and photothermal performance of boron nitride nanosheets (BNNS)-conjugated poly(3-hexylthiophene) (P3HT) composite. The composite shows improved thermal conductivity of 4.40 Wm−1K−1 at 30 wt% BNNS loading, which enhances 511 % relative to the pure P3HT film. Furthermore, with the assistance of hot-pressing approach, its thermal conductivity could be increased to 5.19 Wm−1K−1 at the same loading. Additionally, the composite exhibits excellent photothermal property that the surface temperature of BNNS-P3HT can rise to ∼98.3 °C after 120 s under 808 nm laser light irradiation with power density of 1.31 W/cm2. [ABSTRACT FROM AUTHOR]

[Display omitted] • A bottom-up strategy for producing isotropic liquid metal network in polymer. • Liquid metal composites can be applied for high-performance thermal management. • The approach is applicable for various liquid metal filler of different viscosity. • Thermal conductivity was controlled by volume fraction of filler and size of TPE. • A high intrinsic thermal conductivity (up to 32.71 W/mK) was obtained. This work presents a bottom-up approach to construct an isotropic network of liquid metal in polymer, and such generated isotropic liquid metal network brings large enhancement on the thermal and electrical conductivity of the composite for 3D thermal management. The building blocks are composed of polymer particles coated with liquid metal. The liquid metal starts to flow and fill the gaps between the polymer particles, and fuses with each other to assemble into a continuous liquid metal network in the polymer matrix under the mechanical load during heating. The continuous filler network provides effective paths for thermal and electrical conduction, and thus enhances the thermal and electrical conductivity of the composites. Using biphasic copper-eutectic gallium indium as the filler, we generated polymer composites with thermal conductivity as high as 32.71 W/m·K (90 vol%; under compression) and electrical conductivity up to 1.18 × 106 S/m. Moreover, the measurement of the in-plane and cross-plane thermal diffusivity reveals the isotropic enhancement of thermal conductivity in such composites, which may help expand the potential application of these composites in 3D thermal management, flexible electronics, energy conversion and soft robotics. [ABSTRACT FROM AUTHOR]

[Display omitted] • A W-Cu vapor chamber (VC) improves thermal management systems at high temperature. • A Cu coating layer enhances bonding strength with wick and isolates working medium. • The lateral thermal conductivity of W-Cu VC is ~1700 W/(m∙K) under 1.6 kW/cm2. • The W-Cu VC reduces the thermal stress at the interface between the VC and chip. The electronic industry is facing pressing needs for cooling system with high-performance in heat transfer and matched coefficient of thermal expansion (CTE) with the chips. Metal composite materials (MCMs) with low CTE can be used in cooling chips to overcome the thermal expansion mismatch between the cooling substrate and chips. However, low thermal conductivity of MCMs limits their application in electronic cooling systems. Increasing the percentage of components with high thermal conductivity can enhance the thermal conductivity of MCMs, but it often leads to increase CTE as well. Here, we demonstrate that vapor–liquid phase change can improve the heat transfer performance of tungsten-copper (W-Cu) alloy-based MCMs while maintain their low CTEs. Such strategy reduces the maximum temperature and thermal resistance of MCMs, and also allows for heat spreading from concentrated heat source with high power density. The W-Cu alloy-based vapor chamber (VC) has low thermal resistance of 0.38 K/W at 100 W and high lateral thermal conductivity of ~1727 W/(m·K). The W-Cu alloy-based VC can be readily integrated with the chip and heat sink to serve as cooling substrates for dissipating the heat and simultaneously lowering the thermal expansion mismatch by using its high thermal conductivity and low CTE. [ABSTRACT FROM AUTHOR]

• Erythritol is impregnated within surface-roughened hydrophilic copper foam. • Thermal conductivity and supercooling degree are simultaneously improved. • A latent-heat releasing percentage of 85.8% is achieved. • Medium-temperature solar-thermal energy harvesting is demonstrated. • Conversion of medium-temperature heat into usable electricity is demonstrated. Erythritol (ET) has received increasing research attention for medium-temperature phase change solar-thermal energy storage. However, ET suffers from serious supercooling, low thermal conductivity, poor solar absorption and leakage after melting, which lead to low solar-thermal energy harvesting and releasing efficiency. Herein, we simultaneously overcome these inherent shortcomings by impregnating ET within surface-roughened hydrophilic copper foam, which is prepared by subsequent oxidization of commercial copper foam and thermal reduction under hydrogen, and using stably dispersed crumpled graphene particles as the solar-thermal converter. Such oxidization-reduction-treated copper foam not only provides numerous heterogeneous nucleation sites and lowers the nucleation energy barrier for forming ET crystals during the solidification process, but also facilitates rapid charging and discharging along three-dimensional heat conductive networks, and confines the melted ET. Compared with neat ET, the copper foam-templated composites have reduced the supercooling degree by ~60 °C and improved thermal conductivity by more than 5 times, which in turn lead to a large latent-heat releasing percentage of 85.8% and a high heat-extraction efficiency of 94.2%. We demonstrate that such composites can be used for high-efficiency, medium-temperature, form-stable, direct solar-thermal energy harvesting, and the harvested heat can be readily converted into electricity to power small devices. [ABSTRACT FROM AUTHOR]