My sresearch: The solovphoresis motion of polystyrene (PS) particles occurs in the presence of a concentration gradient of non-electrolyte solutions. By leveraging the property that ethanol can permeate through PDMS, a stable and continuous ethanol concentration gradient can be established in a microchannel to induce the motion of PS particles. This setup allows the investigation of the effect of gravity on the solovphoresis motion of PS particles.