Combustion of hydrogen-oxygen mixture in nanobubbles

Observation of a spontaneous reaction between hydrogen and oxygen in bubbles in water whose diameter is smaller than a threshold value around 150 nm is presented. The effect is attributed to high Laplace pressure and to fast dynamics in nanobubbles and is the first indication on combustion in the nanoscale. The bubbles were produced by water electrolysis in specially designed microchips using successive generation of H2 and O2 above the same electrode with short voltage pulses in the microsecond range. Diferent signatures indicating the combustion process are described.