LAUSR

Here, we introduce the novel concept of 'soft shuttle' for transportation, manipulation and diffusion studies of small liquid droplets using electrowetting on dielectric mechanism. This method enables manipulation of droplets several times smaller than the electrode size and importantly minimises evaporation, contamination and exposure of the sample to high voltages. We demonstrate various modes of droplet loading, transporting and unloading. Using advanced imaging processing techniques, we obtained detailed information about shuttle and droplet centroids. Furthermore, varying water concentration on the 'soft shuttle' allows for modulating the diffusion kinetics of samples into the shuttle, which also can be controlled with 'soft shuttle' actuation velocity. We believe that this novel approach for the manipulation of droplets will advance the field of droplet-based open microfluidics, and can be potentially useful for applications in biotechnology, diagnostics, or analytical chemistry.