Search results for "Fluidics"

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.

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…

3D printed fluidic platform with in-situ covalently immobilized polymer monolithic column for automatic solid-phase extraction

2020

Abstract In this work, 3D stereolithographic printing is proposed for the first time for the fabrication of fluidic devices aimed at in-situ covalent immobilization of polymer monolithic columns. Integration in advanced flow injection systems capitalized upon programmable flow was realized for fully automatic solid-phase extraction (SPE) and clean-up procedures as a ‘front-end’ to on-line liquid chromatography. The as-fabricated 3D-printed extraction column devices were designed to tolerate the pressure drop of forward-flow fluidic systems when handling large sample volumes as demonstrated by the determination of anti-microbial agents, plastic additives and monomers as models of emerging co…

One-piece micropumps from liquid crystalline core-shell particles

2012

Responsive polymers are low-cost, light weight and flexible, and thus an attractive class of materials for the integration into micromechanical and lab-on-chip systems. Triggered by external stimuli, liquid crystalline elastomers are able to perform mechanical motion and can be utilized as microactuators. Here we present the fabrication of one-piece micropumps from liquid crystalline core-shell elastomer particles via a microfluidic double-emulsion process, the continuous nature of which enables a low-cost and rapid production. The liquid crystalline elastomer shell contains a liquid core, which is reversibly pumped into and out of the particle by actuation of the liquid crystalline shell i…

Asymmetric nanopore rectification for ion pumping, electrical power generation, and information processing applications

2011

Single-track, asymmetric nanopores can currently be functionalised with a spatially inhomogeneous distribution of fixed charges and a variety of pore tip shapes. Optimising the asymmetric nanopore characteristics is crucial for practical applications in nanofluidics. We have addressed here this question for three cases based on different input/output chemical and electrical signals: (i) ion pumping up a concentration gradient by means of a periodic, time-dependent bias potential, (ii) information processing with a single nanopore acting as the nanofluidic diode of a logic gate, and (iii) electrical energy harvesting using a nanopore that separates two solutions of different salt concentrati…