text: On superhydrophobic surfaces, liquid drops are observed to bounce off of the solid surface. Richard and Quéré showed that a small liquid drop was able to bounce off of a solid surface over 20 times before coming to rest. Of particular interest is the length of time that the drop remains in contact with the solid surface. This is important in applications such as heat transfer and aircraft icing. To find a relationship between drop size and contact time for low Weber number impacts (We ) and capillarity () can be used, as follows:
  where  is the drop density, R is the drop radius,  is the characteristic time scale, and  is the drop surface tension.
  This yields
  The contact time is independent of velocity in this regime. The minimum contact time for a low deformation drop (We << 1) is approximated by the lowest-order oscillation period for a spherical drop., giving the characteristic time a prefactor of approximately 2.2. For large-deformation drops (We > 1), similar contact times are seen even though dynamics of impact are different, as discussed below. If the droplet is split into multiple droplets, the contact time is reduced.
   By creating tapered surfaces with large spacing, the impacting droplet will exhibit the counterintuitive pancake bouncing, characterized by the droplet bouncing off at the end of spreading without retraction, resulting in ~80% contact time reduction.