The increasing power density and miniaturization of certain electronic devices demand lightweight heat spreaders that offer high thermal conductivity while maintaining electrical insulation. This study compares two electrically insulating heat-spreading solutions: (i) a highly filled hexagonal boron nitride (hBN)–polymer composite film serving as an intrinsically insulating heat spreader, and (ii) a graphene-assembled film combined with a Kapton insulating layer. Custom-fabricated hBN films (~200 μm thick) with strong in-plane alignment and ~93 wt% hBN content were characterized using Scanning Electron Microscopy (SEM), thermo-gravimetric analysis (TGA), and electrical breakdown voltage measurements. Both heat-spreader configurations were experimentally evaluated under identical thermal loading using a customized thermal test rig, complemented by numerical modeling to assess the influence of lateral dimensions. Experimental results show that for larger lateral sizes (40 mm diameter), the graphene/Kapton configuration achieves lower heater temperatures and reduced thermal resistance due to graphene’s high in-plane thermal conductivity. However, modeling indicates that as the heat-spreader diameter decreases, the performance of the graphene/Kapton configuration degrades more rapidly, whereas the hBN-based film becomes comparatively more effective due to its superior through-plane heat-transfer capability. Electrical testing further confirms that the hBN-based heat spreader shows significantly higher partial discharge (PD) and surface flashover voltages. These findings underscore the critical role of anisotropic thermal transport and lateral size in the design of electrically insulating heat spreaders for advanced power-electronics thermal management.

The rapid development of microsupercapacitors (MSCs) has increased demand for high-performance electrode materials that can provide long-lasting energy storage with high power and energy densities. Sputtered iridium oxide film (SIROF) is a promising option due to its superior pseudocapacitive behavior, scalability, and compatibility with microfabrication techniques. In this work, we have explored sputtered iridium oxide films (SIROF) with a platelet morphology as electrode materials for on-chip microsupercapacitors. The electrochemical performance of the devices is systematically evaluated in a variety of electrolytes including acidic, neutral, alkaline, gel, and ionic liquid systems. Among aqueous electrolytes phosphoric acid (H3PO4) delivers the highest areal capacitance of 48.6 mF cm(-2). The PVA/H3PO4 gel electrolyte provides enhanced cycling stability, retaining 99.5% of its capacitance after 10,000 cycles and exhibits reduced self-discharge. The ionic liquid EMIM TFSI enables higher energy and power densities through an extended operating voltage window and stable operation at elevated temperature of 60 degrees C. These findings provide valuable insights into the impact of electrode/electrolyte interaction on the overall performance of SIROF. Additionally, the MSCs demonstrate scalable operation and can be efficiently charged using commercial photovoltaic cells, highlighting their potential for integration into self-powered microelectronic systems. These results highlight the versatility of SIROF electrodes and their suitability for next-generation micro-energy storage applications.

To enhance the thermal management capabilities of epoxy composite, inspired by Baumkuchen, a simple, scalable, and environmentally friendly process was proposed. The graphene strips, without any chemical modification, were integrated into assembled graphene paper, and the vertically aligned graphene strips/epoxy composite with the tree-ring structure was prepared by the rolling cutting method. The composite exhibited an extremely high through-plane thermal conductivity of 49.2 W/mK, which was 289 times higher than that of pure EP. Additionally, the composite also possesses a range of desirable properties, including good electromagnetic interference shielding, efficient Joule heating, and remarkable mechanical performance. These properties further expand the application of graphene-based thermal interface materials in the field of thermal management of electronic devices.

With increasing attention paid to wearable devices and flexible sensing technologies, flexible electronics, as an interdisciplinary field integrating materials science and micro/nano manufacturing, is rapidly entering a stage of application expansion. Laser-induced graphene (LIG) technology is considered one of the potential pathways for graphene preparation for high-performance flexible electronic devices. This study explores the temperature feature and the transformation mechanism of flexible PI films into graphene under CO2 laser irradiation from a multi-scale perspective. A solid heat transfer model was constructed based on the finite element method to dynamically simulate the temperature field distribution on the PI surface during laser scanning. The results show a highly linear positive correlation between temperature and laser energy density. Furthermore, the thermal decomposition evolution of PI in the range of 2800-3400 K was analyzed using molecular dynamics simulations based on a reactive force field. The microscopic simulation results show that the generated LIG possesses a larger specific surface area at higher temperatures, exhibiting the optimal density distribution of hexagonal carbon ring structures when the temperature reaches 3400 K.

Graphene, due to its exceptional mechanical, optical, electrical, physical and thermal properties, has attracted strong interest for both fundamental studies and real applications. Among all these properties, the extraordinary high thermal conductivity makes graphene an ideal cooling material for power devices and systems. In mean time, rapid growth of information and AI technology continues to push power density and integration level in electronics devices, leading to an increase in greater heat dissipation causing lower performance, and shorter operating life. In this paper, the technology of a new graphene-enhanced thermal interface material (GT-TIM) manufacturing process is described. The effect of bonding pressures on thermal performance of the GT-TIM with different thicknesses is presented. The immersion test up to 1-month in immersion condition was carried out. The results show that the GT-TIM can be exposed to very high bonding pressure without delamination, well beyond normally used bonding pressure regions and extremely low thermal resistance in the range of 4-5 Kmm2/W at 40 psi (276kPa) at a thickness of 0,2 mm. In a typical biocompatible coolant environment, the thermal performance is basically intact after one month´s exposure. It is thus concluded that that this class of the novel GT-TIM has very interesting feature that can potentially be used for many large power cooling applications, especially for immersion cooling.

This study presents a detailed performance evaluation of a graphene-enhanced thermal interface material (TIM) conducted at RISE ICE Data Center. Tests were performed on Open Compute Project (OCP) Leopard servers using three different TIMs: conventional thermal paste, graphene-enhanced thermal pad GT90 from SHT Smart High Tech AB (SHT), and indium foil. Three sets of experiments were conducted: (1) air cooling with default chassis fan control in a bespoke server wind tunnel, (2) air cooling with controlled, fixed fan speeds and different heatsink mounting pressures operating in the wind tunnel and (3) immersion cooling tests with two coolant flow rates at fixed inlet temperatures. Results indicate that graphene-enhanced TIM and thermal paste exhibit similar performance in experiment (1), whereas indium foil TIM tests showed the undesired effect of increased CPU temperatures. In experiment (2), servers equipped with graphene-enhanced TIM showed lower CPU temperatures in comparison to the servers equipped with Indium foil TIM. In experiment (3), immersion cooling resulted in lower CPU temperatures overall, with the graphene-enhanced TIM again providing lower temperatures than indium foil at a similar mounting pressure. The findings suggest that the interfacial thermal conductivity and material compatibility of the GT90 TIM contribute to an improved performance in the tested immersion cooling system as well as the importance of mounting pressure.

The trend towards miniaturization of electronics and increasing transistor density in semiconductors requires more efficient cooling solutions. Vapor chambers are well established passive cooling devices that are used in a wide variety of electronics. Commercial vapor chambers are often made of high-density metals such as copper which can be a downside in lightweight applications such as laptops, smartphones, and tablets. In this study, different novel lightweight graphene-enhanced vapor chambers were built using graphene-assembled film with high thermal conductivity as envelope material. The thermal performance of the designed graphene-enhanced vapor chambers was characterized in a customized test rig and compared to a copper vapor chamber. One of the graphene-enhanced vapor chambers was shown to have 21.6% lower thermal resistance than that of a copper vapor chamber with the same design. A mass-based thermal resistance parameter was introduced as a figure of merit to account for the superior low density of the graphene-enhanced vapor chambers. The mass-based thermal resistance of the graphene-enhanced vapor chamber was seen to be 46.5% lower than that of the copper vapor chamber. The result of this study shows that replacing copper with graphene-assembled film as envelope in vapor chambers can both reduce thermal resistance and decrease the mass of the device. Hence, it is believed that graphene-enhanced vapor chambers have great potential for replacing conventional metal-based vapor chambers in lightweight and high-performance electronics and power module cooling applications in the future.

Continuously higher integration levels in (opto-)electronics require new solutions and materials for thermal management of excess heat. Here we investigate the integration of graphene-based heat spreader films with printed circuit board (PCB) assembled, high-power light emitting diodes (LEDs), as used in modern automotive lighting, using industrially highly scalable screen printing and stencil printing of the graphene-based films. We compare screen/stencil printing of graphene heat spreaders on the PCBs from archetypical water-and ester-based inks and characterize the resulting graphene heat spreaders with respect to printing fidelity and resolution, film microstructure, electrical and thermal properties and their performance in lowering LED temperatures during LED operation. Importantly, we use only comparatively low graphene film curing temperatures (150 degrees C) that are compatible with industrial PCB/surface-mounted-device (SMD) LED integration processes. We find that screen-printed, ester-based graphene heat spreaders result in a modest reduction of LED temperature during operation of on average-2 K with a maximum reduction of-4 K. Generally, our work establishes the feasibility of scalable screen and stencil printing for integration of graphene films with state-of-the-art PCB/SMD assemblies.

Multifunctional and eco‐friendly thermal interface materials with bidirectional thermal conductivity have become outstanding materials for solving the heat dissipation problem of electronic devices. The remarkable thermal and mechanical properties of graphene establish it as a promising material for thermal management. This study introduces an environmentally friendly strategy to construct an effective thermal conductive path by assembling and stacking recycled graphene strips (GS) under external mechanical force and using them as reinforcement to strengthen epoxy resin (EP) composites. By adjusting the loading of GS, a superior vertical thermal conductivity of 104.6 W mK−1 is achieved accompanied by a parallel thermal conductivity of 10.6 W mK−1, representing enhancement of 614 and 61 times compared to that of the pure EP, respectively. The outstanding bidirectional thermal conductivity, along with ultralow thermal resistance, strong electromagnetic interference shielding, high‐efficiency Joule heating, as well as excellent mechanical properties, offers a promising way to address the thermal management challenges of next‐generation electronic devices.

In this work, graphene-enhanced thermal interface materials (GT-TIM) were investigated for their thermal stability by employing isothermal calorimetry and thermogravimetric analysis. Moreover, the potential for incorporating GT-TIM in electronics packaging processes was evaluated by subjecting samples to industrially standardised reflow heat profiles before tensile stress and thermal testing. Finally, we performed reliability tests on GT-TIM regarding the thermal impedance of samples subjected to isotherms around decomposition temperatures. The results indicate that GT-TIM is stable up to 180°C and can withstand standardised reflow processes and exposure to elevated temperatures in the 150°C to 200 °C range with only a 10-20% increase in thermal impedance. The excellent thermal stability and performance of GT-TIM at these temperatures would make it a promising alternative within high-power dissipation to replace solder foils for TIM1 and thermal pastes, thermal putties, phase change materials (PCMs) as well as low thermal performance pads in TIM1.5 and TIM2 application in an electronic system.

The requirement for efficient heat transfer to ensure the reliable operation of electronics devices is paramount. Thermal interface materials (TIMs), such as thermal grease and phase change materials, are extensively used globally to reduce thermal contact resistance and ensure optimal performance. In this paper, reliability of a graphene-enhanced TIM is characterized. In real applications, under certain circumstances, TIMs may experience mechanical compression or external pressure, leading to repetitive compression. This compression can affect the performance and mechanical stability of the TIMs. To study this, a Micron-Displacement Pressure Measurement Device with elevated ambient temperature measurement capability is used. This equipment enables us to study mechanical compression at specific temperatures and pressures, allowing the TIM to undergo multiple cycles of compression. In total, the mechanical cycling tests were done up to 5000 cycles. Through this procedure, the durability and potential fatigue damage of the graphene enhanced TIM is studied. The results show that the graphene enhanced TIM does not have significant thermal or mechanical degradation up to 5000 cycles. This suggests that reliability of the graphene enhanced TIM under mechanical loading is extremely good leading to potential use in electronics power module cooling applications.

Recent advances in materials science have shown that solid-state thermal interface materials (TIM) enhanced with graphene are becoming a viable substitute to thermal pastes and phase change materials (PCM) in electronics packaging with high power densities. Such graphene-enhanced TIM (GT-TIM) can ex-hibit comparable or lower thermal impedance than their thermal pastes and PCM counterparts, yet do not degrade under high heat flux. This makes them interesting for several applications, especially data centers and cloud computing. However, graphene has very high electric conductivity, thus increasing the risk of short circuits due to the release of graphene particle residues during handling, installation, or repeated use. Before becoming a viable alternative to high-power electronics in the industrial sector, the problem of potential short-circuiting must be resolved. In this paper, we investigated the release of particle residues from untreated and surface-coated GT-TIM by employing a unique abrasion method in which samples were abraded at a constant rate with constant applied pressure. The results show that the amount of particle residues released from the GT-TIM correlates to the pressure used for the TIM assembly and that surface coatings can significantly reduce the release of abraded particles at applied pressures at 12 kPa or lower. This work provides an insight into design considerations for a bonding/assembly/packaging process of the unique GT-TIM, enabling findings of optimum design and packaging conditions of using them for addressing the high-performance dissipation of novel and large power electronics systems.

With the pursuit of electronics product performance, the thermal management of electronics devices is becoming increasingly prominent. It is well-known that graphene film (GF) has very good heat dissipation properties, while metal materials have excellent mechanical properties and anti-aging properties. If they are prepared into laminated materials, which can be used as the shell of heat pipes, vapor chambers and other heat dissipation devices to improve heat dissipation capacity. In this study, we developed a set of new GF/metal laminates and fabricated a new type of lightweight and high thermal conductivity GF/Ti laminated material with an out-plane thermal conductivity of 8.64 Wm-1K-1.

As electronic equipment becomes increasingly lightweight, miniaturized, and highly integrated, the heat dissipation challenges of electronic devices become increasingly greater. Heat pipes are among the most efficient heat-conducting elements. However, conventional heat pipes are gradually unable to meet the heat dissipation needs and lightweight requirements of electronic devices due to limitations in the intrinsic thermal conductivity of the metal and weight constraints. Therefore, it is imperative to explore new high thermal conductivity and lightweight heat pipes. This paper developed a new graphene-reinforced nickel-based heat pipe and a graphene-reinforced aluminum-based heat pipe. The results show that the two graphene-reinforced heat pipes significantly reduce the mass of the heat pipe and improve the heat transfer performance of the heat pipe.

This study reviews the latest advances in hexagonal boron nitride stripping technology, including various exfoliation methods. The advantages, disadvantages and principles of these techniques are analyzed, in addition to the influencing factors, in order to provide a comprehensive understanding of the latest technologies for future research directions in hexagonal boron nitride. It was shown that the choice of stripping agent directly affects the stripping results, and during the stripping process, temperature, pressure and stripping speed, the stripping conditions have a great influence on the structure and properties of the crystals. It was also found that physical properties such as thickness, surface roughness and crystalline quality of the exfoliated flakes are important factors affecting the thickness of the final h-BN layer, and that these parameters directly influence the thermal and mechanical properties of the material, as well as its stability and reliability in equipment applications. The dispersion, morphology and size distribution of the dispersions were also found to be key parameters affecting cluster formation and thermal properties. These parameters affect the homogeneity and enhancement of the dispersions in the material, which directly affects the performance of the final formulation. We have also focused on the chemical properties of the exfoliated sheets and dispersions, such as surface chemistry and surface energy. These properties not only affect the interfacial compatibility and adhesion of the material, but also have a significant impact on its stability and reactivity in a given environment.

With the continuous development of electronic devices, effective heat dissipation has become a major factor affecting service life. Thermal interface materials (TIM) play a key role in controlling heat dissipation of electronic devices and have thus attracted widespread attention. In this study, we used graphene flakes (GF) derived from graphene film that is wasted during the preparation of commercial large-scale graphene-enhanced TIMs as thermally conductive fillers to formulate a new TIM. The thermal conductivity of the developed TIM is 50% higher with GFs than without. Furthermore, the TIM has a tensile strength of 0.46 MPa with an elongation at break of 1225%, a maximum compression strength of 0.64 MPa at 50% compression, and high mechanical cycle stability. This report provides a cost-efficient and environmentally friendly approach to producing high-performance TIMs for electronic cooling applications.

As the most effective heat transfer device, heat pipes have received widespread attention, but traditional heat pipes may be difficult to meet heat dissipation requirements in the near future. Since graphene was discovered, its ultra-high thermal conductivity has been the focus of people's research and application. Therefore, the combination of graphene and heat pipes is a method to improve the performance of existing heat pipes. This paper is a critical assessment of recent advances in graphene-based heat pipes. In the paper, we conducted a simple theoretical analysis of the operation of the heat pipe, and also summarized the research status, enhancement mechanism, and enhancement method of graphene-enhanced heat pipes, and predicted the future development direction. The results show that depositing graphene-based materials on wicks, using graphene-based nanofluids, and application of graphene composites are effective ways to enhance the performance of heat pipes.

With increasing demands of high-performance and functionality, electronics devices generate a great amount of heat. Thus, efficient heat dissipation is crucially needed. Owing to its extremely good thermal conductivity, graphene is an interesting candidate for this purpose. In this paper, a two-step temperature-annealing process to fabricate ultrahigh thermal conductive graphene assembled films (GFs) is proposed. The thermal conductivity of the obtained GFs was as high as 3826 ± 47 W m −1 K −1 . Extending the time of high-temperature annealing significantly improved the thermal performance of the GF. Structural analyses confirmed that the high thermal conductivity is caused by the large grain size, defect-free stacking, and high flatness, which are beneficial for phonon transmission in the carbon lattice. The turbostratic stacking degree decreased with increasing heat treatment time. However, the increase in the grain size after long heat treatment had a more pronounced effect on the phonon transfer of the GF than that of turbostratic stacking. The developed GFs show great potential for efficient thermal management in electronics devices.