<P> Top - down and bottom - up are two approaches for the manufacture of products . These terms were first applied to the field of nanotechnology by the Foresight Institute in 1989 in order to distinguish between molecular manufacturing (to mass - produce large atomically precise objects) and conventional manufacturing (which can mass - produce large objects that are not atomically precise). Bottom - up approaches seek to have smaller (usually molecular) components built up into more complex assemblies, while top - down approaches seek to create nanoscale devices by using larger, externally controlled ones to direct their assembly . Certain valuable nanostructures, such as Silicon nanowires, can be fabricated using either approach, with processing methods selected on the basis of targeted applications . </P> <P> The top - down approach often uses the traditional workshop or microfabrication methods where externally controlled tools are used to cut, mill, and shape materials into the desired shape and order . Micropatterning techniques, such as photolithography and inkjet printing belong to this category . Vapor treatment can be regarded as a new top - down secondary approaches to engineer nanostructures . </P> <P> Bottom - up approaches, in contrast, use the chemical properties of single molecules to cause single - molecule components to (a) self - organize or self - assemble into some useful conformation, or (b) rely on positional assembly . These approaches utilize the concepts of molecular self - assembly and / or molecular recognition . See also Supramolecular chemistry . Such bottom - up approaches should, broadly speaking, be able to produce devices in parallel and much cheaper than top - down methods, but could potentially be overwhelmed as the size and complexity of the desired assembly increases . </P> <P> These terms are also employed in neuroscience, cognitive neuroscience and cognitive psychology to discuss the flow of information in processing . Typically sensory input is considered "bottom - up", and higher cognitive processes, which have more information from other sources, are considered "top - down". A bottom - up process is characterized by an absence of higher level direction in sensory processing, whereas a top - down process is characterized by a high level of direction of sensory processing by more cognition, such as goals or targets (Beiderman, 19). </P>

Give an original example of a top-down and bottom-up process