| 摘要 |
A method of manufacturing a composite material. A catalyst material (12) is deposited on a substrate (4), the catalyst material (12) being patterned to form an array of catalyst regions. Each catalyst region has an outer periphery which has no rotational symmetry and/or no mirror symmetry. A first array of bundles of filaments is grown on the substrate (4), growth of the filaments being catalysed by the catalyst material (12). Each bundle and each filament has a base (14, 14a, 22) attached to one of the catalyst regions and a free tip (15). Each bundle comprises a plurality of filaments spaced apart from adjacent bundles in the array by an interstitial gap (30). The bundles are impregnated with a capillary forming liquid (18) which is then evaporated so that the free tips (15) of the filaments are drawn together within each bundle and the bundles become distorted. These steps are repeated to provide a second array of distorted bundles of filaments which are positioned or grown so that the bundles of one array are positioned at least partially within the interstitial gaps (30) of the other array. The bundles of filaments and the interstitial gaps (30) are impregnated with a matrix material (19, 33, 43). The bundles typically become distorted due to their lack of symmetry. For instance they may become tilted, twisted, or distorted in some other way. The nature and orientation of the distortion can be controlled easily by tailoring the shape and orientation of the catalyst region, enabling the composite mate¬ rial to possess a desired anisotropic mechanical or electromagnetic property. |
