Self-cleaning device and method using electrical oscillation and mechanical oscillation

A self-cleaning device comprising:

• at least one first electrode disposed on a solid material layer;
• a first dielectric layer disposed on the at least one first electrode;
• a hydrophobic layer disposed on the first dielectric layer;
• at least one mechanical oscillation unit;
• and
• a controller,
• wherein electrical oscillation for oscillating a droplet in a horizontal direction is generated by applying a first electric signal to the at least one first electrode, thereby merging droplets formed on the hydrophobic layer,
• the mechanical oscillation unit moves the merged droplets in a specific direction or atomizes the merged droplets to remove the merged droplets by generating mechanical oscillation for oscillating the droplets in a vertical direction,
• each of the droplets has a volume smaller than 3 μl, a new droplet having a volume more than 3 μl is generated by the merging, and the mechanical oscillation unit is not activated when the electrical oscillation is generated to merge the droplets but is activated after the droplets are merged,
• the controller controls to generate selectively the electrical oscillation or the mechanical oscillation, and to generate the mechanical oscillation after the electrical oscillation is generated according to a situation of the droplets formed on the hydrophobic layer.