Harnessing the Power of Flagellar Motors

Tethered Escherichia coli (E. coli) flagellar motors are incorporated into a series of MEMS devices to provide mechanical power. Device examples include a microfluidic pump and a micro AC dynamo. An E. coli cell is about 3 mum long and 1 mum in diameter, with several flagella that are driven at the base by rotational flagellar motors. The microfluidic pump is realized through the tethering of a harmless strain of E. coli cells to a glass micro channel. The pump operates on the viscous pumping principle where a fluidic conveyor belt formed by the rotating tethered cells `drags' fluid from one end of the channel to the other. Hydrodynamic loading is used to synchronize cell rotation and also measure the torque capability of the tethered cells. The micro dynamo is realized through integrating 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 result indicates a high power density when compared to other biologically based micro power generators