Traditionally, materials selection has been limited in high-aspect-ratio micromechanical applications, due primarily to the predominance of microfabrication processes and infrastructure dedicated to silicon. While silicon has proven to be an excellent material for many of these applications, no one material can meet the needs of all applications. This is especially evident in biomedical microdevice applications, where the intrinsic brittleness of silicon limits its utility, thus illustrating the need for development of viable alternatives. Titanium is particularly promising in this regard, due to its toughness, biocompatibility, and fatigue resistance. However, lack of sufficient fabrication capability has limited its use in micromechanical systems thus far.
Recently, we reported the development of novel micromachining processes that now enable realization of this promise. These processes, based on plasma etching techniques derived from microelectronics manufacturing, provide for the first time, the capability for fabrication of complex, micrometer-scale, high-aspect-ratio structures in titanium. As such, these processes extend the state of the art in titanium micromachining and do so in a manner that is inherently scalable to low-cost/high-volume manufacturing. The focus of this talk will be to detail these processes, their capabilities, and their use in the fabrication of micromechanical devices for biomedical applications.