Wafer assembly

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

EqiJlpment Includes Wafer Processing- Test - Assembly... 

The potential of photolithography for the construction of protein microarrays has also been demonstrated (Mooney et al., 1996). For these experiments, antibodies were assembled in precise two-dimensional patterns on silicon wafers. This was accomplished by first forming a self-assembled monolayer of n-octadecyltrimethoxysilane (OTMS) on a silicon-dioxide... 

Fluorescence studies and the binding interaction of Quartz/APES/RB with single- and double-stranded oligonucleotides (ssDNA and dsDNA) in Tris-HCl buffer solution of pH 7.4 were carried out. Quartz/APES/RB exhibited emission at 576 nm, whereas Quartz/APES without BB where nonfluorescent, suggesting that RB successfully assembled on the surface of quartz wafers. By comparison with Aem of 5 x 10 5 M RB solution, which was 588 nm, a hypsochromic shift was found. Considering the fluorescence microscopical image of Quartz/APES/RB, it... 

In a subsequent publication [68] the influence of the substrate on the self-assembly process was elucidated. The comparison of a polyimide substrate with a native oxide (Si( )A) covered wafer revealed that differences in interac-... 

FIGURE 15.9 Representative SEM images of [PDDA/MWNT] (a), [PDDA/MWNT]3 (b), and [PDDA/ MWNT]5 (c) assembled on a silicon wafer. The scale bar in (a)—(c) was 5 pm. (d) represents the SEM image of [PDDA/MWNT] 1 with a high amplification with a scale bar of 1 pm. (Reprinted with permission from [54]. Copyright (2004) American Chemical Society.)... 

Figure 11.5. Langmuir-Blodgett (LB) technique-assisted NW assembly (a) Schematic of LB-guided assembly. NWs are floated on a water surface and compressed through computer guided pressure, (b) SEM image of silver NWs deposited on Si wafer. Reprinted with permission from Ref. 54. Copyright 2003 American Chemical Society.

Figure 11.12. Si electrode and NW hybrid device, (a) Schematic of a single LED fabricated by the method outlined in Fig. 11.11. (b) I-V behavior for a crossed p-n junction formed between a fabricated p+-Si electrode and an n-CdS NW. (c) EL spectrum from the forward biased junction, (d) SEM image of a CdS NW assembled over seven p+-silicon electrodes on a SOI wafer (e) EL image recorded from an array consisting of a CdS NW crossing seven p+-Si electrodes. The image was acquired with +5V applied to each silicon electrode while the CdS NW was grounded. [Reprinted with permission from Ref. 59. Copyright 2005 Wiley-VCH Verlag.]...

A small serial production has been set up at the Institute for Instrumental Analysis to develop and demonstrate the fabrication of the microsystem. The production can be subdivided into four phases The wafer-based formation of the fundamental structure, the packaging stage including separation, housing assembly and contact formation of the chips, the deposition of the gradient membrane and the final annealing treatment [4, 5]. 

FIGURE 10.2. Schematic of the two-substrate experiments. An alumina plate was positioned above a Si wafer, separated by 0.66 mm. The whole assembly was placed in the middle of the quartz tube. [Chem Comm 2005]—Reproduced by permission of The Royal Society of Chemistry, (ref 54)... 

Separation of SWNTs based on chirality and diameter with surfactants has also been evidenced by density-gradient ultracentrifugation [86]. Finally, a recent study has demonstrated the separation of semiconducting nanotubes from metallic ones by chemical interaction of the former with attached amine-terminated silane molecules assembled on a silicon wafer. In a separate experiment, metallic nanotubes were also... 

Fig. 9 Fluorescence spectra of a 5-PAA/PP wafer that was first aminoamidated with NH2CH2CH2N(CH3)2 and then treated with 11 in a pH 7 buffer. The first spectrum (a) is the ionic assembly that forms at pH 7 from ion pairing of-N(CH3)2H groups of the graft with - C02 groups of the polyfacrylic acid). The second spectrum (b) shows complete removal of 11 after treatment of the interface with 0.1 N NaOH (which converts the -N(CH3)2H groups to -N(CH3)2 groups)...

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