微流体

Abstract(#br)We investigate in this work the formulation of composite resistive pastes based on epoxy resins and graphite for micro-heater manufacturing via thick-film technology. The resistive paste is first screen-printed onto a printed circuit board (PCB) substrate, and then coated with expandable polydimethylsiloxane (PDMS), a composite based on an elastomeric matrix and expandable microspheres, resulting into one-shot thermal actuators allowing pumping and sealing in microfluidic devices.

Abstract(#br)SU-8 and polydimethylsiloxane (PDMS) are both transparent materials with properties very convenient for rapid prototyping of microfluidic systems. However, previous efforts of combining these two materials failed due to poor adhesion between them. Herein, we introduce a promising low-temperature technique (\u003c 100 °C) to irreversibly bond two or more structured layers of SU-8 and PDMS to create hybrid stacks. This offers new possibilities in design and fabrication of enclosed three-dimensional microstructures and microchannels with simple soft-lithography techniques.

Abstract(#br)We present leakage-free valves and an efficient fixed-volume mixer fabricated using a four-layer soft lithography technique in polydimethylsiloxane (PDMS). Mixing is achieved with a 95% efficiency in a few seconds by creating circular flow patterns inside a simple rectangular chamber. Pressurized air is used to actuate control chambers for active valving and mixing. In our device, neither the mold nor the microfluidic channel requires complex designs.

Abstract(#br)The scope of this paper is development of a new laboratory-on-a-chip (LOC) device for biomedical studies consisting of a microfluidic system coupled to microelectronic/optical transducers with nanometric features, commonly called biosensors. The proposed device is a hybrid system with sensing element on silicon (Si) chip and microfluidic system on polydimethylsiloxane (PDMS) substrates, taking into accounts their particular advantages.

Abstract(#br)Microfluidic channel systems were fabricated out of polydimethylsiloxane (PDMS) and used as culture vessels for primary culture of neurons from locust thoracic ganglia. In a biocompatibility study it was shown that cell adhesion and neuronal cell growth of locust neurons on uncoated PDMS was restricted. Coating with concanavalin A improved cell adhesion. In closed-channel microfluidic devices neurons were grown in static-bath culture conditions for more than 15 days.

Abstract(#br)We will describe the use of an alternative polymer which is suitable for use in microfluidic applications which require the use of harsh chemicals or aggressive solvents. Currently microfluidics systems are mainly manufactured in polydimethylsiloxane (PDMS) due to its ease of use, and the ability to produce monolithic microfluidic valves directly into the same material as the microfluidic chip.

Abstract(#br)A novel method, a 3D printing technique, in particular, acrylic photopolymer material-based Rapid Prototyping (RPT) have been used to 1) fabricate molds for PDMS (PolyDiMethylSiloxane) casting; 2) fabricate RPT-based microfluidics and 3) fabricate RPT-based research instrument platforms. 3D RPT-based molds have been fabricated in order to cast a PDMS flow cell for a Surface Plasmon Resonance (SPR) instrument, and to cast a PDMS chamber for cell lysis in a nanobiological sensor.

Abstract(#br)In this communication we demonstrate a conception of an artificial microkidney using pertinent microtools that more accurately mimic organ functions in vitro . We present a technique to integrate polyethersulfone (PES) membranes usually used in hemodialysis inside a polydimethylsiloxane (PDMS) microchip. The purpose of the microchip is to model glomerular filtration “on-chip”.

Abstract(#br)DNA extraction automation is a major concern in molecular diagnostic where processing of numerous and daily samples of blood represent a labor-intensive task and are difficult to automate. With the rapid growth in the area of DNA diagnostics, there is an URGENT need for the development of a micro total analysis system which can do all the three main steps involved during nucleic acid-based diagnostics: sample preparation, extraction of the DNA, detection and quantification on one SINGLE chip.

Abstract(#br)We present a microfluidic cell plate for endocrine disrupting chemicals (EDCs) detection, like estrogenic activity, in waterish solution. This platform technology consists of four independent micro flow units made of polydimethylsiloxane (PDMS) and glass, which enables a selective detection of up to four species of the EDCs per one-way chip containing the corresponding immobilized receptor. The concept of the detection is based on direct fluorescence analysis.