Experimental evidence is presented that combustion can ignite at room temperature spontaneously inside microbubbles filled with mixture of hydrogen and oxygen. We perform water electrolysis in a closed microchamber by voltage pulses of alternating polarity at repetition frequencies 100 kHz to pump the gases rapidly into the electrolyte and produce extreme supersaturation with both gases. After a delay of 300 600 ls, we observe stroboscopically microbubbles of 5 20 lm in diameter that appear in between the electrodes for several microseconds. Each event is accompanied by a pressure jump of 0:1 1 bar that is measured interferometrically. The pressure jumps are attributed to combustion of the gases in the microbubbles.
Postnikov, A. V., Uvarov, I. V., Prokaznikov, A. V., & Svetovoy, V. (2016). Observation of spontaneous combustion of hydrogen and oxygen in microbubbles. Applied physics letters, 108(12), 121604-. . https://doi.org/10.1063/1.4944780