title: Highly energetic phenomena in water electrolysis.
abstract: Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2and O2gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.
authors.affiliation: Yaroslavl Branch of the Institute of Physics and Technology, Russian Academy of Sciencies, Universitetskaya 21, Yaroslavl, 150007, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Postnikov
authors.affiliation: Yaroslavl Branch of the Institute of Physics and Technology, Russian Academy of Sciencies, Universitetskaya 21, Yaroslavl, 150007, Russia.
authors.forename: I V
authors.initials: IV
authors.lastname: Uvarov
authors.affiliation: P. G. Demidov Yaroslavl State University, Sovetskaya 14, Yaroslavl, 150000, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Lokhanin
authors.affiliation: Yaroslavl Branch of the Institute of Physics and Technology, Russian Academy of Sciencies, Universitetskaya 21, Yaroslavl, 150007, Russia.|MESA+ Institute for Nanotechnology, University of Twente, P. O. Box 217, Enschede, 7500 AE, The Netherlands.
authors.forename: V B
authors.initials: VB
authors.lastname: Svetovoy