They may be simple bacteria, but they have an expert take on the principles of fluid dynamics.
Bugs such as Escherichia coli move by rotating a rod-like flagellum that trails from their cell wall. Experiments now show that this swimming stroke is no wild flailing, but a subtle technique to maximise thrust.
To model the movement of a bacterium’s flagellum through water, mechanical engineer Bian Qian and colleagues at Brown University in Providence, Rhode Island, lowered an elastic rod into oil – they used oil as it simulates the viscosity of water at the scale of bacteria. The top end of the rod was connected to…
