A review on self-assembly in microfluidic devices

Abstract

Self-assembly is a process that operates over a vast range of length and time scales. Microfluidic technology has been proven to be a powerful tool to manipulate micro- and nano-scale substrates with precise control over size and speed using various fluidic materials and properties. In this review, we discuss the current status of microfluidic technology in manipulating fluid dynamics and interfacial phenomena which influence self-assembly process and resulted structures. The self-assembled materials/structures were summarized and discussed as the sequence of the objective size at the micro-, nano- and molecular scale. Overall, microfluidics is becoming a useful tool to manipulate various fluids regarding to physical and chemical properties, being inherently suitable for self-assembly process control.

Wet spinning and radial self-assembly of a carbohydrate low molecular weight gelator into well organized hydrogel filaments

“…Some studies described the use of shear stress, 26,[29][30][31][32][33] controlled reagent exchanges in microfluidic devices, [34][35][36][37][38] electrical 39 or magnetic fields, 40,41 surface effects [42][43][44] or ice growth 45 to control self-assembly. While microfluidics is often used to control the self-assembly of micelles, particles, liquid crystals and some polymers, 46,47 it is scarcely the case for molecular gels. Concerning the Gal-C7 hydrogel, the direct shearing of the gel to promote alignment was not possible because this kind of gel undergoes strong synaeresis when a mechanical stress is applied.…”

Oil Motion Control by an Extra Pinning Structure in Electro-Fluidic Display

“…To EFD, an oil/water two-phase microfluidic system, the oil motion control is the key for its optical performance, like gray scale, switching response, maximum aperture ratio, oil contraction direction, and so on [ 4 , 5 ].Therefore, the dynamic of oil/water interfacial movement attracts great attention in this field [ 6 , 7 , 8 , 9 , 10 , 11 ]. For a typical EFD pixel ( Figure 1 ), which is sub-millimeterin size, the dominant driving forces for oil motion are recognized as interfacial tension and electrostatic force [ 12 ]. The interfacial boundary is normally described by the Young-Lippmann equation.…”

Driving Waveform Design of Electrowetting Displays Based on an Exponential Function for a Stable Grayscale and a Short Driving Time

“…For typical submillimeter-scale EWD pixels, the main driving forces of the ink movement are the interface tension and electrostatic force. The interface boundary is usually described using the Young-Lippmann equation [22,23], as shown in Equation 1:…”