| 摘要 |
A method is disclosed of producing a hollow structure, and particularly of forming channels of very small cross-sectional dimensions in a body of etchable material. In carrying out the method, a composite element is formed by providing a surface portion of a body (2) with a layer (3) of material resistant to etching medium for the body, the layer being interrupted to expose an area (4) of the body surface, etching medium is applied to the body at the interruption to etch a cavity (5) in the body beneath the resistant layer (3), and a further layer of material (3A, 3B) is provided on a surface of the composite element in the region of the interruption and/or the etched cavity. In a typical variant, the further layer is built up until it closes the interruption thereby forming a closed formation which may be an elongate tubular passage (6). |
