From a two-dimensional chemical pattern to a three-dimensional topology through selective inversion of a liquid–liquid bilayer

Abstract

Soft organic surfaces with more and more complex topologies are required daily to engineer appropriate microstructures for many different applications such as DNA array technology, biological optics for advanced photonic systems and microfluidics. Complementarily to conventional lithographic processes, several pioneering methods have been developed recently, by controlling phase separation of polymer blends, spinodal decomposition of homopolymers or by using the action of additional external forces driving diverse instabilities. Here we present a method that not only provides original concepts towards the three-dimensional (3D) structuring of liquids, on the basis of the synergistic effects of molecular diffusion and confined nucleation, but also suggests original solutions for the transport, mixing and filtering of small volumes of liquid. Through the intrinsic destabilization of a liquid-liquid bilayer, the 2D pattern of a chemically structured surface with 'hydrophilic' and 'hydrophobic' domains is transferred to a solid/liquid interface as a 3D topography with either 'positive' or 'negative' replication. This easy-to-use process has potential applications in various technological realms requiring a specific topography at interfaces such as microfluidics or biosensors.

Evolution of nonconformal Landau-Levich-Bretherton films of partially wetting liquids

“…• with air, and PDMS-ethanol-air Hamaker constant A = 2 × 10 −21 J calculated from [12]. Flows at low speeds (C < 2.5 × 10 −5 ) showed no deposition of fluid on the wall [ Fig.…”

“…We calculate the friction experienced by a flowing bubble, expressed as the pressure jump across the bubble, as p B = ( p − RU wh)/n, where n is the total number of bubbles in the device. The hydrodynamic resistance, R, in the liquid segments is equivalent to flow without bubbles and given by R = η [12…”

Self-Organized Micropatterning of Thin Viscous Bilayers Under Microgravity

“…The lack of long-range order in the dewetted structures hinders the utility of dewetting as a viable surface patterning technique for engineering of small structures. Thus, much theoretical (Konnur et al 2000;Kargupta and Sharma 2001Thiele et al 2001Thiele et al , 2003Brusch et al 2002;Simmons and Chauhan 2006;Kao et al 2006;Saprykin et al 2007) and experimental (Higgins and Jones 2000; The amplitude of the roughness on the surface is denoted by a Sehgal et al 2002;LeOpoldes and Damman 2006;Mukherjee et al 2008) effort has been directed in exploring the mechanisms and conditions required to align the self-organized dewetted structures by the use of physically and chemically heterogeneous substrates.…”

Stimuli‐Responsive Hybrid Coatings of Polyelectrolyte Multilayers and Nano‐Patterned Polymer Brushes

“…[1,2] In order that chemical or biological adsorbents or fluids can be effectively contained and controlled in the limited surface area of such miniaturized devices, it is essential that the organic films can be easily coated and micro-patterned at the thickness of nanometer scale. [3][4][5][6] The surface properties adaptive or responsive to external chemical or physical stimuli, such as pH, temperature, or solvent quality, are additionally desired for such application of thin organic coatings. [7] In this regard, we create a new nanoscopic hybrid film with a stimuli-responsive property, by combining two chemically distinct polymeric nano films, polyelectrolyte multilayers (PEM) and nanopatterned polymer brushes (NPB).…”