Search results for "Microfluidic"

Control of the Properties of Micrometer-Sized Actuators from Liquid Crystalline Elastomers Prepared in a Microfluidic Setup

2010

In this article new results on the preparation of monodisperse particles from a liquid crystalline elastomer in a microfluidic setup are presnted. For this, droplets from a liquid crystalline monomer are prepared in a microfluidic device and polymerized while they are flowing inside a microtube. The parti­cles obtained by this method possess an internal orientation, which gives them actuating properties. When they are heated into the isotropic phase of the liquid crystalline material they show a reversible change in shape whereby they change their length in one direction by almost 100%. It is shown how the variation of experimental parameters during their synthesis impacts the properties of…

Infrared microspectroscopy of biochemical response of living cells in microfabricated devices

2010

Abstract First experiments demonstrating the suitability of novel microfabricated fluidic devices for measuring living cells in physiological environment by synchrotron radiation (SR) Fourier Transform Infrared microspectroscopy (μ-FTIR) are presented. The devices were fabricated on CaF 2 windows, using the photoresist XARP 3100/10 to define the liquid cell lay-out. Therefore, the sample holder is transparent to both visible and infrared light, robust, completely recyclable and with a precise spacing. Using prototype devices of thicknesses 9, 5 and 3 μm, we studied the response of the U937 monocytic cell line to mechanical compression. The temporal evolution of the FTIR spectra, characteris…

Microfluidic production of hyaluronic acid derivative microfibers to control drug release

2016

"Available online 4 July 2016"

Direct Writing of Channels for Microfluidics in Silica by MeV Ion Beam Lithography

2011

The lithographic exposure characteristic of amorphous silica (SiO2) was investigated for 6.8 MeV16O3+ions. A programmable proximity aperture lithography (PPAL) technique was used for the ion beam exposure. After exposure, the exposed pattern was developed by selective etching in 4% v/v HF. Here, we report on the development of SiO2in term of the etch depth dependence on the ion fluence. This showed an exponential approach towards a constant asymptotic etch depth with increasing ion fluence. An example of microfluidic channels produced by this technique is demonstrated.

MICROFIBRE CELLULA-ADESIVE DI UN DERIVATO DELL’ACIDO IALURONICO PER APPLICAZIONI IN INGEGNERIA TISSUTALE

2016

An integrated Tissue Engineering approach to Human Bronchial model: Biodegradable Scaffold and Microfluidics Platform

L’ingegneria tissutale è la combinazione di cellule, materiali e metodi di ingegneria, insieme con opportuni fattori biochimici e fisico-chimici, volta a migliorare o sostituire le funzioni biologiche di tessuti danneggiati [1, 2]. A tal proposito supporti porosi e sistemi microfluidici sono utilizzati per scopi di ingegneria tissutale. Scaffold polimerici biodegradabili sono stati sfruttati come supporti strutturali per rigenerare vari tessuti quali ossa, cartilagini, nervi, legamenti, pelle e fegato. Una geometria porosa aperta con canali interconnessi è un prerequisito per la crescita cellulare ad alta densità e per un trasporto di nutrienti, ossigeno e prodotti di scarto metabolici. …

The liquid state of FG-nucleoporins mimics permeability barrier properties of nuclear pore complexes

2019

Nuclear pore complexes form a permeability barrier in vivo that regulates nucleocytoplasmic transport. Here, the authors present a microfluidic device that couples rapid liquid–liquid phase separation of nucleoporins with direct optical interrogation. Freshly formed liquid nucleoporin droplets mimic permeability barrier properties of NPCs.

Towards micrometer sized core-shell actuators from liquid crystalline elastomers by a continuous flow synthesis

2012

We present here the successful preparation of liquid crystalline core-shell elastomers via a microfluidic double-emulsion process. The customized set-up allows for a temperature-controlled fabrication of the core-shell particles from a thermoresponsive mesogenic monomer. The nematic liquid crystalline shell is filled with a non-mesogenic core of silicone oil. To verify the core-shell structure with optical microscopy, we prepared particles with a colored core using a red dye. We were also able to micro-manipulate the particles and penetrate them with a small glass capillary to extract the liquid core.

Effects of confinement and external fields on structure and transport in colloidal dispersions in reduced dimensionality

2012

In this work, we focus on low-dimensional colloidal model systems, via simulation studies and also some complementary experiments, in order to elucidate the interplay between phase behavior, geometric structures and transport properties. In particular, we try to investigate the (nonlinear!) response of these very soft colloidal systems to various perturbations: uniform and uniaxial pressure, laser fields, shear due to moving boundaries and randomly quenched disorder.We study ordering phenomena on surfaces or in monolayers by Monte Carlo computer simulations of binary hard-disk mixtures, the influence of a substrate being modeled by an external potential. Weak external fields allow a control…

Artificial multiple criticality and phase equilibria: an investigation of the PC-SAFT approach

2005

The perturbed-chain statistical associating fluid theory (PC-SAFT) is studied for a wide range of temperature, T, pressure, p, and (effective) chain length, m, to establish the generic phase diagram of polymers according to this theory. In addition to the expected gas-liquid coexistence, two additional phase separations are found, termed "gas-gas" equilibrium (at very low densities) and "liquid-liquid" equilibrium (at densities where the system is expected to be solid already). These phase separations imply that in one-component polymer systems three critical points occur, as well as equilibria of three fluid phases at triple points. However, Monte Carlo simulations of the corresponding sys…