Recearch Projects

Roughness design towards reversible non- / full-wetting surfaces:
From Fakir Droplets to Liquid Films

(The "HYDROFAKIR" project is funded by the European Research Council)

The realization of tunable surfaces that are able to undergo reversible transitions between superhydrophobic and superhydrophilic behaviour is a challenging and vital issue due to their potential use in applications involving self cleaning, very low flow resistance, and liquid handling without moving mechanical parts.

Superhydrophobic surfaces arising from micro-scale roughened hydrophobic materials spontaneously exhibit transitions to become superhydrophilic when their material wetting properties are suitably modified by external stimuli. The reverse transition, however, requires external actuation/ perturbation which can be so strong that presumably deteriorates the liquids handled and therefore limits the use of such techniques in applications.

In this project we plan to combine continuum and mesoscale computational analysis of wetting phenomena in solid surfaces to create “designer roughness” that will minimize, or even eliminate, the strength of the actuation required to achieve full- to non-wetting reversibility. The modelling will be done in a continuous dialogue with surface fabrication and wetting tests. Wetting experiments will be performed along with novel microactuation techniques for liquid interfaces.

Selected Publications

  • N. Chamakos, G. Karapetsas and A. G. Papathanasiou “How asymmetric surfaces induce directional droplet motion.”Colloids and Surfaces A: Physicochemical and Engineering Aspects, 511, 180-189, 2016 [link].

  • G. Karapetsas, N. Chamakos and A. G. Papathanasiou “Efficient modelling of droplet dynamics on complex surfaces” Journal of Physics: Condensed Matter, 28(8), 085101, 2016.[link]

  • N. Chamakos, M. E. Kavousanakis, A. G. Boudouvis and A. G. Papathanasiou "Droplet spreading on rough surfaces: tackling the contact line boundary condition." Physics of Fluids, 28, 022105, 2016.[link]

  • G. Pashos, G. Kokkoris, A. G. Papathanasiou and A. G. Boudouvis "Wetting transitions on patterned surfaces with diffuse interaction potentials embedded in a Young-Laplace formulation." Journal of Chemical Physics, 144, 034105, 2016. [link]

  • Michail E. Kavousanakis, Nikolaos T. Chamakos, and Athanasios G. Papathanasiou “On the Connection of Intrinsic Wettability and Surface Topography with the Apparent Wetting Behavior and Adhesion Properties.” Journal of Physical Chemistry C, 119, 15056, 2015.

  • Christos Boutopoulos, Marianneza Chatzipetrou, Athanasios G. Papathanasiou and Ioanna Zergioti "Time resolved imaging and immobilization study of bioliquids on hydrophobic and superhydrophobic surfaces by means of Laser-Induced Forward Transfer." Laser Physics Letters, 11, 105603, 2014.

  • Nikolaos T. Chamakos, Michail E. Kavousanakis and Athanasios G. Papathanasiou "Neither Lippmann nor Young: Enabling electrowetting modeling on structured dielectric surfaces." Langmuir, 30(16), 4662, 2014.

  • Nikolaos T. Chamakos, Michail E. Kavousanakis and Athanasios G. Papathanasiou "Enabling efficient energy barrier computations of wetting transitions on geometrically patterned surfaces." Soft Matter, 9, 9624, 2013.

  • Michail E. Kavousanakis, Carlos E. Colosqui, Athanasios G. Papathanasiou "Engineering the geometry of stripe-patterned surfaces towards efficient wettability switching." Colloids and Surfaces A: Physicochemical and Engineering Aspects, 436, 309, 2013.

  • Christos Boutopoulos, Dimitrios P. Papageorgiou, Ioanna Zergioti and Athanasios G. Papathanasiou "Sticking of droplets on slippery superhydrophobic surfaces by Laser Induced Forward Transfer." Applied Physics Letters, 103, 024104, 2013.

  • Ravi Prakash, Dimitrios P. Papageorgiou, Athanasios G. Papathanasiou, Karan V. I. S. Kaler "Dielectrophoretic Liquid Actuation on Nano-Textured Super Hydrophobic Surfaces." Sensors & Actuators: B. Chemical, 182, 351, 2013.

  • C. E. Colosqui, M. E. Kavousanakis, A. G. Papathanasiou and I. G. Kevrekidis "Mesoscopic model for microscale hydrodynamics and interfacial phenomena: Slip, films, and contact angle hysteresis." Physical Review E, 87(1), 013302, 2013.

  • M. E. Kavousanakis, C. E. Colosqui, I. G. Kevrekidis and A. G. Papathanasiou "Mechanisms of wetting transitions on patterned surfaces: Continuum and mesoscopic analysis." Soft Matter, 8(30), 7928, 2012.

  • R. Prakash, K. V. I. S. Kaler, D. P. Papageorgiou, A. G. Papathanasiou "Performance of Multilayered Fluoropolymer Surface Coating for DEP Surface Microfluidics Devices." Microfluidics and Nanofluidics, 13(2), 309, 2012.

  • E. P. Koumoulos, C. A. Charitidis, D. P. Papageorgiou, A. G. Papathanasiou, A. G. Boudouvis "Nanomechanical and Nanotribological Properties of Hydrophobic Fluorocarbon Dielectric Coating on Tetraethoxysilane for Electrowetting Applications." Surface & Coatings Technology, 206, 3823, 2012.

  • D. P. Papageorgiou, A. Tserepi, A. G. Boudouvis, A. G. Papathanasiou "Superior performance of multilayered fluoropolymer films in low voltage electrowetting." Journal of Colloid and Interface Science, 368, 592, 2012.

  • A. K. Gnanappa, D. Papageorgiou, E. Gogolides, A. Tserepi, A. G. Papathanasiou, A. G. Boudouvis "Hierarchical, plasma nanotextured, robust superamphiphobic polymeric surfaces structurally stabilized through a wetting-drying cycle." Plasma Processes and Polymers, 9(3), 304, 2012.

  • Invited paper

    D. P. Papageorgiou, E. P. Koumoulos, C. A. Charitidis, A. G. Boudouvis and A. G. Papathanasiou "Evaluating the robustness of top coatings comprising plasma-deposited fluorocarbons in electrowetting systems." Journal of Adhesion Science and Technology, 26 (12-17), 2012.