Basic study on nanofabrication of biodegradable plastics applying biochemical machining

Plastics are regarded as proper materials for microfluidic chips, and, in particular, biodegradable plastics will be more appropriate from the viewpoint of environmental friendliness. In addition, when they are utilized as chip substrate, biochemical machining can be applied. Biochemical machining is a process, which utilizes enzymatic biodegradation. This paper describes studies on application of biochemical machining to nanofabrication of poly(l-lactic acid) (PLLA), which is one of the most widely used biodegradable plastics industrially. The degradation performance of enzyme (proteinase K) was experimentally evaluated to extrapolate a suitable condition for nanofabrication. Additionally, in order to make arbitrary channels with nano-order depth on PLLA, mask fabrication was proposed. It is a fabrication method to control degraded regions and obtain desired shapes with a mask, which has penetrating grooves. Using this method, we achieved fabrication of straight grooves with nano-scale depth. In conclusion, it is clear that biochemical machining can realize an effective process of arbitrarily shaped nanogrooves on PLLA.