In Figure 4a, it can be observed that the lengths of the CNTs are inhomogenous and the walls are rough without pretreatment. Figure 4b clearly shows the morphology of CNT arrays with pretreatment. Compared with that of Figure 4a, the lengths of CNTs are perfectly uniform

and aligned with a great enhancement of graphitization degree with pretreatment. The check details brushes based on the CNT arrays with the heat preservation pretreatment may clean the particles better than those without the pretreatment due to their flexibility and recoverability. The reason why heat preservation has so strong effect is that it can change the inner stress distribution of AAO template, thus affect the hole roughness of the AAO template. Figure 4 SEM images of CNTs. (a) Without AZD6244 and (b) with thermal insulation pretreatment. Epoxy resin was adopted as the adhesive of bristles and substrate, because it can avoid corrosion in acid, alkali, and high-temperature atmosphere. In practical applications, brush should combine with different see more substrates to meet multiple requirements, such as electrical conductivity, survivability, and mechanical properties. So different

micro brushes from the CNT arrays were constructed on the substrate of silicon wafer, glass sheet, and polyimide, respectively. In Figure 5a, we can observe that the three micro brushes have toothbrush-like structures, which enable them to meet different requirements and environments. It is shown that the bristles of micro brush have a fairly uniform height. If the bristles and substrate combine loosely, the external force in Liothyronine Sodium practice will lead to severe shedding of bristles which will reduce the lifetime of use. The adhesive degree of bristles and substrate is showed in Figure 5c. The upper part shows the uniform CNT arrays, namely the bristles. It can be clearly seen that the bristles are firmly embedded in epoxy resin and closely combined with the substrate, which

is of great benefit to the use lifetime of micro brushes. The schematic diagram of micro brush is showed in Figure 6. Figure 5 Photo and SEM images of micro brush. (a) Photo of micro brushes, (b) low magnification SEM image of micro brush, and (c) high-magnification SEM image of micro brush. Figure 6 Schematic diagram of micro brush. The research of micro brushes in cleaning the particles in the smooth plane and narrow space will be very meaningful. Figure 7 shows SEM images of the substrate before and after the brush cleaning. In Figure 7a, the particles are found to be almost cleaned from the surface of silicon wafer. The micro brushes were further used to clean rough surfaces, for example, narrow space between the electrode with the width of 100 and 2 μm, as shown in Figure 7b,c.