Thermal routing refers to the ability to direct heat energy from a source to a selected drain, offering great potential for asymmetric thermal path regulation. However, existing approaches to asymmetric heat transport largely rely on phononic band engineering and mechanically moving components, typically limited to heat fluxes at the microwatt level or complicated experimental configurations with long-term reliability concerns. Herein, inspired by the analogy between thermal advection and thermoelectric effects in dragging heat energy, we propose a solid-state thermal metadevice featuring large heat energy flux and near-unity thermal split ratio. By examining the evolutionary path of the Seebeck coefficients, the unique asymmetry-enhancement mechanism arising from the commonly-overlooked Thomson effect is revealed, enabling an improved thermal splitting effect of the device. Free of mechanically moving components, this work provides a new paradigm for the design of solid-state thermal routers with great power and electrical reconfigurability. It makes a promising candidate for compact thermal management and thermal logic processing where asymmetric time-varying heat energy reallocation matters.

High-heat-flux chips in high-performance computing, heterogeneous integration, and wide-bandgap electronics are reaching a thermal-management ceiling: transistor-scale hotspots, dense stacks, and low-conductivity interlayers force heat through resistive, interface-rich paths before it reaches the coolant. Microfluidic cooling can support 10²-10³ W/cm² heat fluxes and higher local loads, yet it is often framed as a competition among microchannels, jets, manifolds, two-phase structures, and high-conductivity spreaders. This review reconstructs the field through thermal-path compression and bottleneck migration, using cooling-boundary location, compressed resistance segment, and residual limit as organizing axes. As cooling advances from package-integrated schemes to embedded/interposer and near-junction architectures, the dominant limit shifts from package-side conduction to hotspot spreading, solid–solid/solid–liquid interfacial resistance, hydraulic allocation, and confined phase instability. Representative architectures are assessed through heat flux, pressure drop, area-normalized thermal resistance, and evidence maturity, emphasizing that record heat flux is not transferable without defined heated area, temperature criterion, coolant state, hydraulic cost, and device boundary. We further distinguish proof-of-concept thermal vehicles from device-relevant, package-compatible, and deployment-oriented platforms by considering manufacturability, sealing and leakage risk, semiconductor-process compatibility, coolant/material compatibility, and scale-up to large-area or multi-chip systems. Interface engineering and diamond-enabled platforms show that high intrinsic conductivity is useful only through reliable, low-resistance, and manufacturable interfaces. This framework recasts microfluidic cooling as near-junction co-design rather than a heat-flux race.

Carbon fibers (CF)/epoxy composites are widely utilized in aerospace and transportation due to their light weight and high specific strength/modulus. However, poor interfacial binding between CF and the epoxy matrix leads to phonon scattering and inefficient load transfer, causing heat accumulation and reduced service life in high-power electronic systems. In this study, CF was coated with a styrene, benzocyclobutene, and methyl methacrylate units containing polymer layer mixed with carbon nanotubes (CNT) through impregnation and drying. The polymer layer was then thermally crosslinked to obtain the polymer and CNT coated CF (CF@(CNT/P)). CF@(CNT/P) was then applied as reinforced fibers and epoxy resin containing a liquid crystal structure as the matrix to prepare CF@(CNT/P)/epoxy composites. The π-π interactions and hydrogen bonds between CF and epoxy resin were enhanced by the benzene ring and ester groups in the polymer, thereby improving the interfacial binding between epoxy resin and CF. CF@(CNT/P)/epoxy composite showed enhanced load-bearing and thermal conduction performance. When the mass fractions of CNT and copolymer in CNT/P/dichloromethane (DCM) solution were 0.03 wt% and 0.1 wt%, respectively, the CF@(CNT/P) had the best interfacial binding to the epoxy resin. The interlaminar shear strength and flexural strength of the CF@(CNT/P)/epoxy composite increased from 23.7 and 252.5 MPa of CF/epoxy composite to 31.4 and 369.1 MPa, respectively. Meanwhile, the in-plane (λ_∥) and through-plane (λ_⊥) thermal conductivity values were improved from 7.15 and 0.31 W/(m·K) of CF/epoxy composite to 10.08 and 0.58 W/(m·K), respectively. The CF@(CNT/P)/epoxy composite also demonstrated an electromagnetic interference shielding effectiveness of 38.6 dB which has broad application in high-power electronic information systems.

Deep eutectic solvent (DES) based nanofluids have gained ample attention owing to their extraordinary thermophysical properties such as wide temperature range and thermal stability. While poor static stability of DES based nanofluids heavily hinders their practical application due to the incompatibility with dispersants. Herein, a novel zinc oxide (ZnO) nanofluids using ethylene glycol and potassium acetate DES for solar thermal utilization were developed. With the aim of addressing the poor stability, a one-step in situ synthesis involving microwave-induced dehydration was employed to prepare self-dispersing ZnO nanoparticles without external dispersants. Thermophysical properties and photothermal performance of nanofluids with varying mass fractions (0.5-5 wt.%) were systematically investigated. Results indicate that ZnO inclusion significantly improves thermal conductivity and photothermal conversion. Specifically, the 5 wt.% sample exhibited a 12% increase in thermal conductivity at 65 °C compared to the base fluid, while the 0.5 wt.% sample demonstrated optimal photothermal response under low light intensity. Additionally, the fluids displayed anomalously enhanced specific heat capacity (up to 14.6%), attributed to the formation of ordered interfacial liquid layers on the high-surface-area ZnO nanoparticles through electrostatic interactions and hydrogen bond rearrangement, offering dual advantages in heat transfer and storage, while maintaining dispersion stability for approximately two weeks, which thus presents a low-cost, stable, and environmentally friendly strategy for developing heat transfer fluids suitable for medium-to-high temperature solar collection systems.

Two-dimensional (2D) heterostructures provide an unusually versatile platform for engineering interfaces at the atomic scale. As these materials move toward electronic, optoelectronic and multifunctional devices, heat flow across their interfaces is emerging as a central factor that governs performance, stability and reliability. Interfacial thermal transport has traditionally been treated as a material-pair-specific conductance that should be measured and optimized. In 2D heterostructures, however, the interface is not a passive boundary with a fixed thermal response. Its conductance is shaped by the structural history, local configuration and dynamic state of the interface. In this perspective, we discuss how interface formation, thermal metrology and microscopic phonon mechanisms together define heat flow across atomically thin heterointerfaces. We highlight how direct growth and transfer assembly create distinct opportunities for lateral and vertical interfaces, how Raman thermometry, pump-probe thermoreflectance and electrical methods quantify interfacial transport, and how elastic transmission, inelastic scattering and interface-specific vibrational states govern nanoscale heat flow. We then consider how intrinsic and external control of 2D heterointerfaces can be used to tune conductance for heat dissipation, local heat confinement, rectification and thermal switching. We argue that the future of the field lies in moving from passive characterization of interfacial thermal conductance toward predictive, spatially resolved and actively controlled heat flow in 2D heterostructures.

Imaging thermal properties at the microscale is crucial for unveiling the structure-property relation and developing next-generation thermal management materials. Here, we apply a frequency-domain thermoreflectance (FDTR) microscopy for imaging the thermal conductivity and interfacial thermal conductance of thermal interface materials (TIMs). A fixture customized for imaging thermal properties of TIMs is developed, where the sample is sandwiched between a silica slide coated with a metal transducer and a substrate wafer, and the thermal transport properties are extracted using a bidirectional thermal model. The thermal conductivity of TIMs loaded with thermally conductive particles is profiled with micrometer resolution, and significant local non-uniformity is observed. Pressure-dependent FDTR imaging during loading and unloading reveals the local redistribution of conductive filler particles. Correlative micro-computed tomography reveals that the high thermal conductivity regions correspond to the aggregation of thermally conductive particles. Further statistical analysis of the FDTR image unveiled the asymmetrical and long-tailed probabilistic distribution of thermal conductivity values. Through statistical modeling, we demonstrate that this asymmetry originates from the lognormal size distribution of microparticles. Our work sheds light on the structure-property relation between microstructure and thermal conductivity distribution of TIMs at the microscale.

Thermal Hall effect (THE) refers to the phenomenon whereby, in a magnetic field, when a longitudinal heat current flows through a material, the heat carriers are deflected, thereby generating a transverse temperature difference between the two lateral edges. The transition from electrical to thermal transport enables this effect to involve a wide range of carriers, thereby providing a unique perspective for investigating complex quantum states in condensed matter physics. THE is increasingly becoming a powerful probe of neutral excitations in materials and is used to explore multifield control phenomena in magneto-thermal-electrical coupled systems. Advances in the field of THE have significantly advanced the study of condensed matter systems under extreme conditions (low temperatures and strong magnetic fields) and have laid the groundwork for exploring novel magneto-thermal-electrical effects in quantum materials. This review systematically reviews recent theoretical and experimental progress on THE, with particular attention to the underlying heat carriers. Through an in-depth analysis of the transport mechanisms of different carriers, quantum material systems that can be used to investigate multicarrier coupled transport are identified, which will significantly facilitate the synergistic control of magneto-thermal-electrical transport in complex interacting systems. Finally, we propose a novel in situ, multiparameter integrated characterization method that enables simultaneous and precise measurement of magnetic, thermal, and electrical parameters on the same micro/nanoscale samples. This approach not only overcomes the limitations of bulk materials but also serves as a key experimental platform for revealing the mechanisms of multicarrier coupled transport in micro/nano samples.