Harnessing fibre-structured plasma shock waves for programmable microsphere propulsion

This study demonstrates a fibre-mediated approach to precisely control microsphere propulsion using laser-induced plasma shock waves. By developing a physical model and combining experiments with simulations, we systematically investigate propulsion dynamics (velocity, distance) and efficiency under varying laser energies, microsphere sizes, and fibre geometries. Spectral analysis confirms that propulsion originates from shock waves generated during air plasma expansion, while directional microsphere trajectories validate the shock wave's spherical propagation predicted by simulations. Crucially, the fibre structure enables directional manipulation of shock waves, achieving programmable microsphere motion. This capability unlocks novel applications including laser billiards and non-contact surface cleaning. The established model quantitatively correlates key parameters, providing a framework for optimizing microsphere manipulation systems. The findings advance laser-based micromanipulation technologies with theoretical and practical implications.