Stiffness-guided motion of a droplet on a solid substrates

  • Speaker:   Prof. Andrey Milchev
  • Institution: Inst. Phys. Chemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
  • Date: 12.06. 2018
  • Place: CEITEC Brno University of Technology


A range of technologies require the directed motion of nanoscale droplets on
solid substrates. A way of realizing this effect is durotaxis, whereby a stiffness
gradient of a substrate can induce directional motion without requiring an
energy source. In biology, directed droplet motion on gradient substrates of
tissue is also known to determine a number of crucial processes in eukariotic
cells pertinent to evolution.
In a series of computer experiments with nano-droplets on substrates with
variable stiffness, carried out by means of Molecular Dynamics simulations [1],
we have found that durotaxis' efficiency is determined by a delicate balance of
the stiffness gradient strength, degree of surface wettability, and even by the
size of the droplets themselves. Our results establish the change in interfacial
energy between the droplet and substrate as the driving force for durotaxis, and
we anticipate that this work will provide further insight into the mechanisms of
nanoscale directional motion that has general implications in novel technologies
and applications in biology and health care.
[1] P. E. Theodorakis , S. A. Egorov , and A. Milchev, J. Chem. Phys. 146, 244705

Download lecture poster