文摘
The anisotropic wet micromachining of silicon, based on a water solution of potassium hydroxide (KOH), is astandard fabrication process that is extensively exploited in the realization of very complex microsystems, whichcomprise cantilevers, membranes, and bridges. A nanostructured self-assembled biofilm of amphiphilic proteins, thehydrophobins, was deposited on crystalline silicon by solution deposition and characterized by variable-angle spectroscopicellipsometry (VASE). This procedure formed chemically and mechanically stable mono- and multilayers of self-assembled proteins. The biomolecular membrane has been tested as masking material in the KOH wet etch of thecrystalline silicon. The process has been monitored by VASE and atomic force microscopy measurements. Becauseof the high persistence of the protein biofilm, the hydrophobin-coated silicon surface is perfectly protected duringthe standard KOH micromachining process.