Novel Methods in Fabricating Silicon Knives for Surgical Applications

Ultra-sharp instruments are necessary in many surgical applications such as corneal, retinal, and neurological surgeries. Conventional diamond blades are always reused, and the metal blades are often reused because of their high cost. This reuse can result in significant performance and bio-safety concerns. Hence, there is considerable research interest in developing affordable, single-use surgical instruments that perform closer to or better than the existing gold standard blades. The aim of this thesis is to describe the design, fabrication, and characterization of ultra-sharp micromachined silicon blades that can construct reproducible surgical incisions. The research is focused on the formation of a Laser In-situ Keratoileusis (LASIK) silicon blade. LASIK is a surgical procedure that corrects nearsightedness & farsightedness. Novel approaches to fabricate microsurgical blades using through-wafer bulk micromachining techniques of off-axis wafers are introduced. Two different approaches are taken: a simplified single-mask layer approach yielding a testable silicon blade and a more complicated dual-mask approach yielding an ideal structure close to that of a conventional metal blade. The surgical blades are successfully fabricated and have been characterized by our partners at USC\u27s Doheny Retina Institute. Promising results have been observed, i.e., the silicon surgical blades have outperformed the gold standard metal blades