Micro-printing

A micro reactor concept proposed by MIT and DuPont on the basis of electronic circuits is the most prominent among the examples listed for the hybrid approach [19,101]. The so-called turnkey multiple micro-reactor test station relies on the use of standard components originating from the semiconductor industry for microchemical processing, the construction being oriented at the concept of printed circuit boards. 

V. Pashkova, K. Gora-Marek, L. Litynska-Dobrzynska, M. Derewihski, 2007 Proc. of Second Inter. Symp. Advanced Micro- and Mesoporous Materials , Varna, Bulgaria, in print... 

There are more issues and complexity to be considered if various micro-electromechanical (MEMS)-type devices are included in the macroelectronics tool kit. As described previously, the materials and devices required for TFTs and circuits can provide adequate electromagnetic (visible and RF) sensitivity for many image-type applications. These materials may also provide satisfactory performance in pressure and strain sensors. Nanotube/nanowire-based devices look promising for various chem-bio sensors.85 However, there is little that is known about the ability to integrate printed microfluidic devices (and other such devices with moving parts) into a roll-to-roll-type process. 

Figure 13.2. Inorganic micro/nanoscale elements derived from wafers can be used to form solution suspensions for delivery to another substrate (e.g., plastic sheet) by casting processes (left frame), or they can be dry transfer printed in a way that preserves their lithographically defined spatial organizations (right frame).

Pricing as well as reliability considerations have led to an almost exclusive use of Si-based (i.e. Si and SOI) micro machined devices. Packaging and assembly has focused on ceramics (A1203, AIN, Low Temperature Co-fired Ceramics LTCC), Printed Circuit Board (PCB-) and Surface Mount Device (SMD-) technology and multichip modules (MCM s). 

Figure 1.8 Schematic diagram of a capillary (one of hundreds) within the printing head of a bubble-jet printer. The resistor heats a small portion of solution, which boils thereby increasing the pressure. Bubbles form within 5 (rs of resistance heating after 10 xs the micro-bubbles coalesce to force liquid from the aperture and a bubble is ejected a further 10 xs later. The ejected bubble impinges on the paper moments afterwards to form a written image. Reproduced by permission of Avecia...

Fig. 20 Patterning DNA arrays by the micro-contact printing method...

Aroxmd the same time, Beckman Instruments (now Beckman Coulter) had begun an array-based product development program focused on the use of modified plastics. Silzel and coworkers (1998) and Matson et al. (2001) of Beckman Coulter were among the first to pursue printing of antibodies onto a plastic surface in a microarray format. Silzel et al. immobilized biotinylated monoclonal antibodies onto an avidin-coated polystyrene surface and performed micro-ELISA-based isotyping of IgG species. Matson et al. 

Figure 4.25 Relationship of spot size and pitch. (From Table 1, ChipMaker Micro Spotting Pin Matrix, http //arrayit.com/Products/Printing/Chipmaker/chipmaker. html)...

This author and coworkers at Beckman Coulter first described the use of a low form 96-well plastic microplate for automated micro-ELISA immunoassays (Matson et al., 2001). The polypropylene plate was first modified by a radiofrequency plasma amination process (Matson et al., 1995) followed by conversion to an acyl fluoride surface chemistry for rapid covalent attachment of biomolecules. Proteins (1 to 2 mg/mL) were prepared in 50 mM carbonate buffer, pH 9, containing 4% sodium sulfate (to improve spot uniformity) and printed using a conventional arrayer system. Approximately 200-pL droplets of monoclonal antibodies (anti-cytokine) were deposited into the bottom of the microwells using a Cartesian PS7200 system equipped... 

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