Master chips

Acrylamide thin layer is formed between the master chip and the empty slide... 

Heating induces transfer of DNA from master chip to the acrylamide layer... 

Fig. 2 Diagram of the nanoprinting process. A master chip is produced with a DNA oligonucleotide silanized with a thiol silane. An acrylamide thin layer is allowed to form between an empty slide coated with acrylic silance and the master chip. After the acrylamide becomes polymerized, the complex is heated for 10-60 s. When the master chip is removed, the acrylamide thin layer will remain attached to the empty slide to form a copy chip. Such a copy process can be done repeatedly from a single master chip...

Failure to maintain procedures to ensure that the device design is correctly translated into production specifications. For example, the [redacted] software source code version 1.6 did not go through a formally documented design transfer process. The source code s electronic file transfer to the master chip before production release was not documented and the approved sonrce code version 1.6 (hardcopy or electronic file) was not retained nnder Docnment Controls. 

Ceriotti and Verpoorte [20] integrated a fritless column for NCEC with conventional stationary phases, which was used for the separation of fluorescein isothiocyanate (FITC)-labeled amino acids. The chips were fabricated in poly(dimethylsiloxane) using deep-reactive-ion-etched silicon masters. The... 

A modular micro structured chemical reaction system (ICS) similar to [R 14] is claimed by Bard [84]. The system can use various replaceable and interchangeable cylindrical or rectangular reactors. Generally, the ICS system can include fluid flow handling and control components, mixers, reaction chip-type units, separator devices, process variable detectors and controllers and a computer interface for communicating with the master control center (see Figure 4.31) [84],... 

Only very few studies with alternative materials and fabrication methods have been published. Ekstrom et al. [35] demonstrated the feasibility of structuring inexpensive polymeric materials by means of a microfabricated master for the production of microchannel systems. The structured polymer film was mechanically clamped between two glass plates to form a closed channel system. Recently, a similar route for the fabrication of microchannel chips that relies on casting of an elastomeric polymer material against a microfabricated master has been presented by Effenhauser et al. [36] (see Sect. 3.4). 

FIGURE 2.12 Fabrication procedure of a PDMS chip (a) silicon master wafer with positive surface relief, (b) pre-mixed solution of Sylgard 184 and its curing agent poured over the master, (c) cured PDMS slab peeled from the master wafer, (d) PDMS slab punched with reservoir holes, and (e) ready-to-use device sealed with another slab of PDMS [159]. Reprinted with permission from the American Chemical Society. 

PDMS chips have also been cast from a glass (not Si) master containing photoresist as the positive relief stmcture [556,960]. PDMS was also cast against... 

A two-mask process has been used to create a glass master containing two levels of positive photoresist relief structures. The master was used to cast a PDMS chip consisting of the channel/chamber (25-30 pm deep) and weir (7-12 pm clearance) [960]. Another two-mask process was used to create a Si molding master consisting of 3-pm-high Si relief stmctures and 25-pm-high photoresist relief structures [364]. 

Moreover, a Zeonor plastic plate, normally used to manufacture CDs and DVDs, was hot-embossed (130°C, 250 psi) using a Si master. The embossed chip (with microchannels 60 im wide and 20 pm deep) was thermally bonded to another Zeonor plate (85°C, 200 psi, 10-15 min) [808], In another report, a 2-mm-thick cyclo-olefin (Zeonor 1020 R) substrate was embossed using a Si master to create 20-pm-wide and 10-pm-deep channels [788],... 

Room-temperature embossing on PMMA (Lucite) and copolyester (Vivak) plates was achieved using a Si master. A hydraulic press was employed to apply the pressure (450-2700 psi). Such a room-temperature operation will prevent breakage of the Si master due to the differences in the thermal expansion coefficients of Si and PMMA. This room-temperature procedure improves the lifetime of the master, so that 100, instead of 10, devices per master can be embossed [177], For comparison, when embossing was performed at 140°C in a convection oven using G-clamps to apply the pressure, the Si template could be used to emboss up to 65 PMMA chips [215]. 

A liquid preparation with solid polystyrene (0.6 g) dissolved in liquid styrene monomer (1.5 mL) was cast against a mold. Polymerization was accomplished with UV irradiation (21°C, 18 h). Solid PS was included to reduce the degree of shrinkage that occurred when monomeric styrene was photopolymerized [85]. In a similar manner, PMMA dissolved in MMA was cast against a Si master. Upon UV polymerization (with BME as the photoinitiator), a PMMA chip is formed. Nearly 100 PMMA chips can be replicated using a single Si master [223]. 

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