Polydimethylsiloxane microfluidic devices

Surface block-graft-copolymerization, based on the photochemistry of N, AT-diethyldithiocarbamate has been applied to precisely design biocompatible and functional surfaces (patterns of immobilized heparin or proteins), as well as block-grafted surfaces on polystyrene [83]. Polystyrene surfaces have also been patterned by immobilization of poly(Af-isopropylacrylamide) by photolithography, and subsequently used for regiospecific cell attachment [84]. Surface modification of polydimethylsiloxane microfluidic devices by UV induced polymer grafting improved the stability of the electroosmotic mobility and improved electrophoretic resolution of peptides [85]. 

The microfluidic devices, often called Christmas tree owing to the pattern of the channels, were fabricated from polydimethylsiloxane (PMDS) using common micro technologies (see Figure 1.69). A mask is formed by using a high-resolution 3300 dpi printer to transfer the CAD pattern to a transparent mask substrate. 

Microfabricated Multichannel Electrospray Ionization Emitters on Polydimethylsiloxane (PDMS) Microfluidic Devices... 

In this approach, a mask with desired geometry is inserted in the microscope to generate a mask-defined UV light beam projection on the monomer stream flowing in a polydimethylsiloxane (PDMS) microfluidics device described earlier. 

The development of a cellular microenvironment in a microfluidic chip starts with device fabrication. The most commonly used material for fabrication is polydimethylsiloxane (PDMS). One of the most important components to develop such platforms is the extracellular matrix (ECM), which is the 3D cellular microenvironment. Different approaches have been followed to pattern the ECM inside the microfluidic device, which will significantly affect the arrangement of cells on the chip. Following this, the target cells are seeded and cultured. Such cell culture techniques would be common for drug screening as well as the fundamental research. But for CTCs detection, usually the antibodies will be immobilized on the chip before introducing the cells. 

PDMS Polydimethylsiloxane, popular structural material for the fabrication of microfluidic devices based on soft lithography RTD Residence time distribution... 

Figure 5.2 Schematic of organic excitation and detection system with microfluidic device for fluorescence detection. Green organic light-emitting diode (OLED) acts as the light source, the polydimethylsiloxane (PDMS) microfluidic chip contains the dye detection volume, and polarizer 2 is used to filter out the excitation light and allows only the emission signal to pass through to the organic photodiode (OPD).

Ultra-thin polymeric film is a polymer layer of the thickness in a nanometric scale deposited on a substrate (see Figure 4.2C). Such silicone films are of great interest due to their use in many areas of scientific and technical applications. Polydimethylsiloxane (PDMS) is one of the most popular silicone-based polymers used in the preparation of silicone films. This polymer has a unique molecular structure and physicochemical properties, which make it suitable for a wide range of applications such as lubricants, sealants, adhesives, eye contact lenses, and microfluidic devices [48]. 

Keywords Polydimethylsiloxane (PDMS), microfluidic devices, surface modification, physical adsorption, inner migration, high... 

Recently Allbritton and Li coated polydimethylsiloxane (PDMS) microfluidic channels with BP [36]. Upon irradiation in the presence of a monomer solution, they were able to graft poly(acrylic acid) and poly(ethylene glycol) monomethoxyl acrylate to the interior walls of the channels. This is a significant achievement since the device did not require disassembly in order to modify the channel walls. The electrophoretic separation of the modified channels was different from the native channels. This technique holds particular promise for the microfluidic separations commimity. 

The most common conhguration for performing on-chip detection has been the embedded hber type of device as listed in Table 1. A typical setup, shown in Fig. 1, includes a light source and fiber for delivery, exit fiber connected to a detection system, microfluidic channel, and liquid delivery components. The fibers are usually embedded in chip materials consisting of polydimethylsiloxane (PDMS), SU-8 epoxy, polymethyl methacrylate (PMMA), or glass [3]. 

The use of polymeric materials in microchips has gained popularity, especially in the fabrication of low-cost, disposable devices [3], It is particularly common to prototype polydimethylsiloxane (PDMS) chips, which can easily be fabricated using the soft lithography technique. This fabrication strategy is considered as a low-expertise route of microscale prototyping. It facilitates creation of micropatterns on a surface or within a microfluidic channel without the need for using photochemical processes [9]. Fabrication... 

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