Three-dimensional object manufacture

The sol-gel process for the production of silica is an industrially widely apphed procedure. The process is usually conducted in homogeneous solution, and it is possible to manufacture nano- or micro-sized particles, clear macroscopic silica objects (monoliths), such as fibres or lenses [17]. Sol-gel processing is commonly conducted at quiescent temperature, and no increased pressure is necessary, which makes this method suitable for LLC templating. The starting material for the sol-gel preparation of silica is an orthoester (alkoxide) of the general structure Si(OR)4, which is hydrolysed in order to formally yield silicic acid. The latter undergoes polycondensation into a three-dimensional network of silicon... 

Virtual workspace A representation of a three-dimensional physical workspace generated by computer software and displayed on a video monitor or similar device. This enables, for example, the inclusion and manipulation of computer-generated objects within the virtual workspace such that designs can be tested and modified prior to manufacturing. 

Three-dimensional printing or additive manufacturing (AM) techniques generally focus on the production of stand-alone, individual objects often for niche markets such as prostheses for medical applications. Recently, Deleersnyder (2013) started to use this technique for textile coating and even the production of accessories for apparel (see Figure 2.1) and other textiles. 

Freeform fabrication methods allow objects to be built as a series of layers directly from a three-dimensional computer representation. These allow only one material to be used at a time, or a material plus a soluble support structure. It is clearly feasible to combine several different materials into a single object, which would allow the building of something much closer to an organism. A report on simple robots, which were allowed to evolve in a virtual environment and then were built by freeform fabrication, shows how evolutionary methods might be applied to manufactured objects. 

Results are presented for different kinds of analyzed objects. Two macroscopic test objects were manufactured from teflon and PVC with diameters of approximately lO cm Fig. 5 shows the macroscopic objects in different orientations together with the three dimensional reconstruction in corresponding orientations. To verify the method, the volumes of these objects were calculated as well as experimentally determined. The maximum deviation between the two methods was 3 %. Fig. 6 shows the reconstruction of a limestone particle with an equivalent diameter Xp = 90 pm. The reconstructions reveal the typical shape characteristics for this material with a relative smooth surface. 

MicroCT is an established technique that has impacted many different fields, including medicine, geology, engineering, and manufacturing. This powerful technology uses X-rays to nondestructively generate three-dimensional geometries and can provide information on the internal features of an object. 

Among the above applications, computer-aided manufacturing (CAM) using UV curable resin, generally called laser rapid prototyping, is a new and expanding technology [6-9]. It converts three-dimensional (3D) objects of... 

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