Packaging electronic devices is a growing challenge as device performance and power levels escalate. As device feature sizes decrease, ensuring reliable operation becomes a challenge. Ensuring effective heat transfer from an integrated circuit and its heat spreader to a heat sink is a vital step in meeting this challenge. The projected power density and junction-to-ambient thermal resistance for high-performance chips at the 14 nm generation are >100 Wcm⁻² and <0.2 °CW⁻¹, respectively. The main bottleneck in reducing the net thermal resistance are the thermal resistances of the thermal interface material (TIM). This review evaluates the current state of the art of TIMs. Here, the theory of thermal surface interaction will be addressed and the practicalities of the measurement techniques and the reliability of TIMs will be discussed. Furthermore, the next generation of TIMs will be discussed in terms of potential thermal solutions in the realisation of Internet of Things.

Silver nanowire arrays embedded inside polycarbonate templates are investigated as a viable thermal interface material for electronic cooling applications. The composite shows an average thermal diffusivity value of $1.89\times {10}^{-5}{\text{m}}^2{\text{s}}^{-1}$ , which resulted in an intrinsic thermal conductivity of $30.3\text{W}{\text{m}}^{-1}{\text{K}}^{-1}$ . The nanowires’ protrusion from the film surface enables it to conform to the surface roughness to make a better thermal contact. This resulted in a 61% reduction in thermal impedance when compared with blank polymer. An $\sim 30\text{nm}$ Au film on the top of the composite was found to act as a heat spreader, reducing the thermal impedance further by 35%. A contact impedance model was employed to compare the contact impedance of aligned silver nanowire-polymer composites with that of aligned carbon nanotubes, which showed that the Young’s modulus of the composite is the defining factor in the overall thermal impedance of these composites.

Three-dimensional (3D) hybrid nanostructured electrodes based on one-dimensional (1D) nanorod arrays have recently attracted great attention owing to their synergistic effect of three-dimensional nanostructures and application in energy storage and conversion devices. Here, we designed a heterostructured supercapattery electrode from a combination of NiO and In₂O₃ with a hierarchical hybrid microstructure on nickel foam (NF). Simultaneous heterogeneous growth of 1D nanorod-supported 3D microflower structures on nickel foam enhanced the non-capacitive faradaic energy storage performance due to the synergistic contribution from hierarchical hybrid nanostructure. The heterostructured electrode exhibits a high specific capacity of 766.65 C g⁻¹ at 5 A g⁻¹ and remains as high as 285.12 C g⁻¹ at 30 A g⁻¹. The composite electrode shows an excellent rate performance as a sandwich type symmetric device, offering a high specific energy of 26.24 W h kg⁻¹ at a high power of 1752.8 W kg⁻¹. The device shows a long term cyclic stability with 79% retention after 50 000 cycles, which is remarkable for an oxide based pseudocapacitor. These results suggest that NiO–In₂O₃ with hybrid micro/nano architecture could be a promising electrode for next generation supercapatteries.