Sensors and electronics use SWCNT less frequently than MWCNT but at significant frequencies. Both SWCNT and MWCNT can be electrically conductive, but SWCNT can also be semiconducting; electronics needing semiconducting CNT thus are likely to need SWCNT. SWCNTs are likely to have more predictable electronic behavior, while the presence of a single structure instead of multiple structures allows them to be physically manipulated and aligned, necessary for use in field-effect transistors and other small device components. On nanometer scale, SWCNTs are likely the only sufficiently predictable CNT that can be used, and on small scale or for proof of principle, known CNTs are important for understanding the behavior of the devices made using them. The single walls of SWCNT makes the paths of electrons through the CNT more responsive to external stimuli and thus more effective as sensors. The availability of SWCNT with defined size and electronic MWCNT can be used in gas sensors, however, 103 and so their reduced cost may make them useful alternatives to SWCNT in nonbiological sensing. Transistors and photonics use SWCNT almost exclusively. Publications discussing composites show the use of SWCNT and MWCNT at similar rates. Many of the functions that are needed for composites can be performed both with SWCNT and MWCNT; both have similar Young's moduli and both can be thermally and electrically conductive. The choice of SWCNT or MWCNT may depend mainly on the fraction of nanotubes that can be tolerated in the composite. 111 In Figure , the landscape of emerging trends in the field of CNTs was mapped by identifying concepts that were found the most frequently in literature from 2020-2022, or that increased significantly in usage in the literature during that time using a NLP-based method. These emerging concepts were grouped into three major areas: properties, materials, and applications with further sub-categorization within each area. Within properties, two notable concepts that were frequently found in CNT literature were thickness and thermal conductivity. Thickness appears to primarily occur in publications wherein CNTs are incorporated in microwave absorbing and electromagnetic interference (EMI) shielding composites, to describe the optimal or tested physical thickness of the shielding material. Thermal conductivity is commonly used in the context of using CNTs to improve the thermal properties of composite materials, and for that reason there is no dominant application that results in the high use of this term. Recently, these composite materials have included phase change materials (PCMs), which are used to store energy in the form of latent heat. In these materials, CNTs are incorporated with a bulk phase change material, such as paraffin, where the high thermal conductivity of the CNTs reduces the amount of time needed for the phase change material to take up and release thermal energy. A major advantage to using CNTs for this purpose is that they can improve thermal conductivity in phase change materials significantly at relatively low concentrations, as shown in a recent study where adding 5 weight % CNTs increased the thermal conductivity of a polyurethane PCM by 2.3 times. In addition, CNTs are used in solar water evaporation devices which convert seawater to freshwater, 118 where low thermal conductivity is desirable to prevent heat loss through conduction. In these devices, CNTs are used primarily to take advantage of their high photothermal conversion efficiency. Recently, it has also been demonstrated that aligned CNTs can be incorporated into self-healing polymer matrices, providing high thermal conductivity to intrinsically self-healing materials; 119 both are critical properties in thermal interface materials used in high-power and dynamic devices.