Nanostructured surface topographies have been successfully fabricated on chitosan and synthetic polymer such as polymethyl methacrylate surfaces. Due to the large surface area, chitosan nanopillars would quickly lose water and shrink in size. The rate of water loss can be retarded by crosslinking the polymer. Genipin is chosen for this purpose and found to retain the shape of the nanopillars. However, the aspect ratio of nanoimprinted chitosan pillars was found to be around 1, which may be too small for effective antimicrobial activity. An alternative technique, electro hydrodynamic patterning, which has the potential for producing much higher aspect ratio pillars from polymers that cannot easily be imprinted, is being developed. Initial results show that extremely large aspect ratio nanofibers can be fabricated. The antibacterial and antifungal functions of these nanotopographic surfaces have been evaluated and found to be effective in certain size ranges against the fungal species Fusarium and Aspergillus, and the bacterium Pseudomonas Aeruginosa.