Search results for "Microfluidic"
showing 10 items of 148 documents
Microfluidic Synthesis of Actuating Microparticles from a Thiol-Ene Based Main-Chain Liquid Crystalline Elastomer.
2016
In this article the microfluidic synthesis of strongly actuating particles on the basis of a liquid crystalline main-chain elastomer is presented. The synthesis is carried out in a capillary-based co-flow microreactor by photo-initiated thiol-ene click chemistry of a liquid crystalline monomer mixture. These microparticles exhibit a deformation from a spherical to a rod-like shape during the thermal-initiated phase transition of the liquid crystalline elastomer (LCE) at which the particles’ aspect ratio is almost doubled. Repeated contraction cycles confirm the complete reversibility of the particles’ actuation properties. The transition temperature of the LCE, the temperature range of the …
Microactuators from a main-chain liquid crystalline elastomer via thiol–ene “click” chemistry
2013
Recently it has been described that liquid crystalline elastomer (LCE) particles of the side-chain type can be prepared in microfluidic devices. Here we present the preparation of micrometer-sized LCE particles of the main-chain type by thiol–ene chemistry. The LCE particles are UV-crosslinked via thiol–ene click chemistry of the nematic monomer, carrying terminal thiol and ene groups, and non-mesogenic tetrathiol and tetraene crosslinkers. The preparation of the LCE particles with a microfluidic device by a continuous “on the fly” technique allows their fast processing with an irradiation time of less than 2 seconds. The resulting particles undergo a temperature-driven volume change up to …
2017
Micro-fluidic pumps as well as artificial micro-swimmers are conveniently realized exploiting phoretic solvent flows based on local gradients of temperature, electrolyte concentration or pH. We here present a facile micro-photometric method for monitoring pH gradients and demonstrate its performance and scope on different experimental situations including an electro-osmotic pump and modular micro-swimmers assembled from ion exchange resin beads and polystyrene colloids. In combination with the present microscope and DSLR camera our method offers a 2 \mu m spatial resolution at video frame rate over a field of view of 3920x2602 \mu m^2. Under optimal conditions we achieve a pH-resolution of …
Mesoscopic Simulation Methods for Studying Flow and Transport in Electric Fields in Micro- and Nanochannels
2012
In the past decades, several mesoscale simulation techniques have emerged as tools to study hydrodynamic flow phenomena on scales in the range of nanoto micrometers. Examples are Dissipative Particle Dynamics (DPD), Multiparticle Collision Dynamics (MPCD), or Lattice Boltzmann (LB) methods. These methods allow one to access time and length scales which are not yet within reach of atomistic Molecular Dynamics (MD) simulations, often at relatively moderate computational expense. They can be coupled with particle-based (e.g., molecular dynamics) simulation methods for thermally fluctuating nanoscale objects, such as colloids or large molecules. This makes them particularly attractive for the a…
M9_Microfluidics_for_CNT
2018
The droplets in contact coalesce when exposed to DEP filed.
M10_Microfluidics_for_CNT
2018
Droplets are preferentially directed to the channel with higher flow rate in the passive sorting junction. When the droplets are exposed to DEP field, the DEP force pull them to the narrower channel.
M12_Microfluidics_for_CNT
2018
The droplets exchanging in the trap causes visible scattering of the laser beam focused on the droplet. The obvious change of laser light intensity can be used for detection of droplet exchange.
M2_Microfluidics_for_CNT
2018
Droplet production in flow-focusing microfluidic device. The droplets are cut off from the water phase flow by pressure of oil from the side channels. The movement of the droplets proves laminar flow in the device.
M4_Microfluidics_for_CNT
2018
Size and frequency of the droplets produced in T-junction as a function of continuous and disperse phase pressure ratio.
M7_Microfluidics_for_CNT
2018
A comparation of two designs of a droplet trap. While the droplet exchange is mediated by direct droplet contact in the symmetric design, a short continuous phase plug mediated the droplet exchange in the asymmetric design.