When the droplet free under the influence of the stress field in space, due to the presence of interfacial tension and a round ball. However, when the droplets and solid surface contact, relative to the size of its final shape depends on the droplet internal cohesion and between the droplets and solid adhesion. When a droplet is placed on the solid surface, the liquid droplets can automatically in solid surface spreading apart, or with solid surfaces into contact angle of liquid droplets.