Fig. 1. Audible sound induced generation of transient domains and spatiotemporally controlled cascade reaction networks.

Schematic of the audible sound induced surface standing wave and generation of corresponding concentric rings (cross-sectional view). Spatiotemporally controlled cascade reaction of substrate S1 with an oxygen responsive enzyme E1 is facilitated at the antinodal domains due to the region-specific dissolution of oxygen. The final product P2 is generated by the reaction of product P1 and substrate S2 with enzyme E2, which is observed as a color pattern.