ABSTRACT
Surface micromachining, as its name suggests, produces structures the surface using a succession of thin-film deposition and selective etching patterning. Bulk micromachining represents a totally different process from surface micromachining. Wet etching micromachining provides a higher degree of selectivity, and it is faster than dry etching micromachining. Bulk micromachining presented a quicker advance in the market because it was easier to make a device that would work as projected. Injection molding was first designed in 1930, and it is a technique widely used, particularly in micromanufacturing. Elastomers are very popular in the fabrication of microstructures using casting because they form hermetic, reversible seals to smooth surfaces by adhesion, like silicon and glass. The micromachining precision of this technique depends mainly on the quality of the optical system, on the energy distribution of the beam, and on the used laser wavelength.
