Study on the mechanism of the interface evolution of dual-bubble coalescence driving micromotors in bulk phase

Self-propelled micromotors serve as a bridge between the microfluidic environments and macroscopic control. They have broad application prospects in targeted drug delivery, biosensors, other fields. The high driving speed of bubble is an irreplaceable advantage practical applications. Bubble convert chemical energy ambient solutions into mechanical through asymmetric surface catalytic reactions to drive their own motion. conversion rate used indicator evaluate force. Pt layer tubular micromotor located on inner wall microtube. Bubbles form inside tube. It released from one end microtubule solution self driven by rebound, with ~10<sup>-10</sup>. Janus microsphere motor near gas-liquid interface utilizes coalesced microsphere, ~10<sup>-7</sup>. In sum, suitable for complex scenarios but has low rate. bubbles efficiency only interface. This paper combines advantages bulk motors utilizing efficiently drive, proposing new method dual coalescence motors. experiment, high-speed camera was record ~100μs process micromotors. Then we investigates initial kinetic micro coalescence. Three sets different bubble/particle size ratios <i>R<sub>b</sub></i>/<i>R<sub>p</sub></i><1, <i>R<sub>b</sub></i>/<i>R<sub>p</sub></i>≈1, <i>R<sub>b</sub></i>/<i>R<sub>p</sub></i>>1 were presented propulsion effects microspheres. defined characterize contribution driving. After simulations pseudo potential lattice Boltzmann method, mechanism motion microspheres revealed. clarified that oscillation caused main reason micromotor, its rebound one-bubble freesurface. research results revealed details at time periods, provided factors such particle ratio displacement confirmed efficient release energy.