Manipulation of Colloidal Particles in Three Dimensions via Microfluid Engineering

Abstract

The assembly of nanoparticles into ordered 3D architectures, which requires more complex spatial arrangements of nanoparticles than 2D, is essential to develop new nano- or microdevices in the fields of biotechnology, magnetic devices, catalysis, and optoelectronics. However, because of the long-distance interactions among the nanoparticles or the applied external force, the movement of nanoparticles cannot be precisely controlled, particularly in multidimensional architectures. Therefore, controlling the 3D architecture remains challenging. In this study, the 3D architecture engineering of colloidal particles by manipulating the microfluid morphology is reported, which produces controllable cross-sections and shapes. The modification of the microfluid morphology, which can be achieved by tuning the physical parameters of the system and the pinning point number, affects the nucleation location, growth rate, and orientation of the architectures. Because of the controllable morphology, the waveguiding distance and direction of 3D architectures can be manipulated. Thus, this study highlights the opportunity for creating morphology-controlled 3D architectures with potential applications in optoelectronics.

Control of Droplet Evaporation on Oil-Coated Surfaces for the Synthesis of Asymmetric Supraparticles

“…The coffee-ring effect has its applications 9 for the construction of complex material assemblies in surface patterning, optics, or electronics 10−12 as well as micro- or nanodevices. 13 However, the heterogeneity of the deposition greatly restricts its development in inkjet-printing, 14 photonics, 15 and biosensors, 16 where uniform deposition is required.…”

Advances in Magnetoresistive Biosensors

“…Alternatively, the silicon substrates and the microfluidic channels can be treated with oxygen plasma to form irreversible chemical bonds [77]. Besides the integration techniques, there have also been extensive studies on the behaviors of MNPs in the microfluidic channels as well as the manipulation of MNPs through various configurations of patterned magnetic materials and different shapes of microfluidic channels [78][79][80]. One example of the manipulation of MNPs in microfluidic channels is through the controlled nucleation, displacement, and annihilation of the magnetic domain walls.…”

Controlled Microstructural Architectures Based on Smart Fabrication Strategies

“…[78] Besides, the flexible droplet templates have shown significant advantages in achieving selfassembled microstructures with high resolution and complex 3D morphology. [79][80][81][82][83] Owing to the surface tension between the droplet and the interface, the solvent evaporation could be controlled by the well-designed microstructures. For example, the rupture of the colloidal suspension was guided by patterned micropillars, forming optimal patterned arrays of liquid bridges.…”

“…Besides, a sandwich-shaped patterning system which pinned the top part of the droplet in the middle layer was used to control the pattern and cross-sections of the generated microstructures. [83] The physical parameters of the system and the pinning point number could be tuned to affect the nucleation location, growth rate, and orientation of the architectures, leading to the final cross-sections of triangle, trapezoid, and dumbbell (Figure 3d).…”

“…f) The damage-tolerant lightweight materials could be achieved by Reproduced with permission. [77,80,83,84,85] Copyright 2015, 2017, 2018,2014, and 2015, Wiley-VCH. Reproduced with permission under the terms of the CC-BY 3.0 license.…”