| Micro-devices are being developed for chemical and biological analysis (increased throughput and smaller analysis amounts and times) and require embedded organic materials that provide potential advantages including filtering. There is a gap in development of organic membrane structures and suspension media in micro scale environments. To fill the need for a micro-channel sieve, a pellicle or a suspension medium, research was conducted to fabricate a device with these features biologically grown in situ. Cellulose, a porous material often used as a membrane material, is not easily incorporated into current micro-fabrication processes. Thus, as an alternative approach, a micro scale bioreactor was designed with Acetobacter-xylinum bacterium which organically produces cellulose in a targeted area. This research resulted in development of a method of incorporating cellulose of bacterial origin in a device with a semi-permeable membrane (or functionalized hydro gel). This can be achieved by providing conditions to enable Acetobacter-xylinum to synthesize the material in a micro scale environment. Findings include a set of parameters and rules that enable bacterial cellulose growth in a micro-environment. Oxygen (influenced by surface area) and food availability (volume of liquid media), and the ratio between the two parameters are the limiting factors for successful cellulose growth. Numerical model of oxygen mass transport through the device is developed to ensure proper oxygen availability. Final proof of concept device is presented to validate the theory. |
