Microscale hybrid devices powered by biological flagellar motors

We are developing a series of micro hybrid devices based on tethered flagellar motors. Examples of the devices include a microfluidic pump and a micro ac dynamo. The microfluidic pump is realized through the tethering of a harmless strain of Escherichia coli (E. coli) cells to a microelectromechanical-systems-based microchannel. Each E. coli cell is about 3 mu m long and 1 mu m in diameter, with several flagella that are driven at the base by molecular rotary motors. The operational principle of the micro pump is based on the viscous pumping effect where continuous rotation of tethered cells in a microfluidic channel forms a fluidic conveyor belt that drags fluid from one end of the channel to the other. We used hydrodynamic loading to synchronize cell rotation in order to maximize the fluid pumping capability. The micro dynamo is realized through the integration of tethered flagellar motors with micro ferromagnetic beads and micro copper coils. The micro dynamo generates ac power by using the tethered cells to create a rotating magnetic field around the copper coils. Preliminary results indicate high-power density when compared to other biologically-based micro power generators.