Fabrication of resonating microfluidic chamber for biofuel production in diatoms (Resonating device for biofuel production)

Diatoms are unicellular brown algae with silica walls. They synthesize and store oil in the form of lipid droplets. Much of the crude oil we use comes from fossil diatoms. Extracting oil from living diatoms, as from any other algae, is a cumbersome and cost ineffective process requiring heavy input of energy. We constructed a resonating microfluidic chamber of dimensions 30 mm × 30 mm × 200 μm which is made up of a silicon wafer (orientation <;110>) attached to a piezoelectric disc. The diatoms in -0.5 mL culture medium containing -2.5 × 10 /ml cells are siphoned with a syringe pump at the rate of 10 μl/min at one end of the chamber. The device is further connected to a function generator and oscilloscope to maintain a resonance frequency of 250 KHz and a static voltage of 500 mV. The resonating device is made to resonate for 2 to 20 min. The resonance frequency causes the diatoms to exocytose oil while retaining cell integrity. The number of cells that are were alive at all stages has been found to be 45-50% which can be used for reviving the cells and hence for oozing of oil again. The resonating microfluidic chamber is thus a prototype for a diatom biofuel solar panel which in the presence of sunlight and small energy input milks oil from diatoms.