A sessile drop is an isolated drop which has been deposited on a solid substrate where the
wetted area is limited by the three-phase contact line and characterized by contact angle,
contact radius and drop height. Although, wetting has been studied using contact angles of
drops on solids for more than 200 years, the question remains unanswered: Is wetting of a
rough and chemically heterogeneous surface controlled by the interactions within the
solid/liquid contact area beneath the droplet or only at the three-phase contact line? After the …