Nanolithography using SAMs

Micro/Nanolithography Using Self-Assembled Monolayers (SAMs)... 

Patterned SAMs are composed of two or more SAMs which are deliberately distributed on specific areas on the surface. They can be fabricated in different ways including microcontact printing and dip-pen nanolithography. Patterned SAMs have been used to attract particular nanostructures like ribbons or wires to particular areas on the surface. They have also been used in the functionalization of biosensors in which the localized SAMs have an affinity for specific cells and proteins. Crystallization on patterned SAMs where the crystals grow in localized areas has also been demonstrated. 

A second class of monolayers based on van der Waal s interactions within the monolayer and chemisorption (in contrast with physisorption in the case of LB films) on a solid substrate are self-assembled monolayers (SAMs). SAMs are well-ordered layers, one molecule thick, that form spontaneously by the reaction of molecules, typically substituted-alkyl chains, with the surface of solid materials (193—195). A wide variety of SAM-based supramolecular structures have been generated and used as functional components of materials systems in a wide range of technological applications ranging from nanolithography (196,197) to chemical sensing (198—201). 

Addition lithography using SPMs on SAMs for fabrication of nanoscale patterned SAMs is extremely important as a technique of SPL methodologies. The most typical application of addition lithography with organothiols as ink on gold is well-known as dip-pen nanolithography (DPN) [86,297]. We will describe this technique in the next section. 

This is one of the most promising routes for the development of better diagnostic-sensing systems. In particular, SAMs are frequently used as ultra-thin organic materials in nanolithography technologies in order to improve the micro- and nanofabrication of medical devices with an optimal balance between time, cost and ease of design. 

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