2009/12/18 by Andrey Sokolov, Mario M. Apodaca, Bartosz A. Grzybowski +1 · 12 citations
Biochemistry, Genetics and Molecular Biology · Engineering · Mathematics · Physics and Astronomy · #Bacillus subtilis #Bacteria #Biology #Brownian motion #Classical mechanics #Collective motion #Geometry #Lipid Membrane Structure and Behavior #Mathematics #Mechanics #Micro and Nano Robotics #Microfluidic and Bio-sensing Technologies #Non-equilibrium thermodynamics #Physics #Power (physics) #Rotation (mathematics) #Thermodynamics #Work (physics)
paper · doi:10.1073/pnas.0913015107
openalex publication_date 2009/12/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/14
Whereas the laws of thermodynamics prohibit extraction of useful work from the Brownian motion of particles in equilibrium, these motions can be "rectified" under nonequilibrium conditions, for example, in the presence of asymmetric geometrical obstacles. Here, we describe a class of systems in which aerobic bacteria Bacillus subtilis moving randomly in a fluid film power submillimeter gears and primitive systems of gears decorated with asymmetric teeth. The directional rotation is observed only in the regime of collective bacterial swimming and the gears' angular velocities depend on and can be controlled by the amount of oxygen available to the bacteria. The ability to harness and control the power of collective motions appears an important requirement for further development of mechanical systems driven by microorganisms.