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Formation of Chemical Patterns on Planar Stamps for Microcontact Printing

IP.com Disclosure Number: IPCOM000013187D
Original Publication Date: 2000-Feb-01
Included in the Prior Art Database: 2003-Jun-17
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Abstract

Disclosed is a strategy to form patterns of chemicals on the surface of an elastomer that can be used as a stamp for microcontact printing. This strategy relies on the direct transfer of ink from a patterned inker pad onto a planar stamp wherever the stamp contacts the inker pad. Thus, the planar stamp can microcontact-print a pattern of chemicals onto a substrate provided that the diffusion of these chemicals on the stamp during the time that elapses between inking and printing is small compared to the dimensions of the patterns to be printed.

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Formation of Chemical Patterns on Planar Stamps for Microcontact Printing

   Disclosed is a strategy to form patterns of chemicals on the surface of an elastomer that can be used as a stamp for microcontact printing. This strategy relies on the direct transfer of ink from a patterned inker pad onto a planar stamp wherever the stamp contacts the inker pad. Thus, the planar stamp can microcontact-print a pattern of chemicals onto a substrate provided that the diffusion of these chemicals on the stamp during the time that elapses between inking and printing is small compared to the dimensions of the patterns to be printed.

     Microcontact printing (mCP) is a lithographic technique for which a micropatterned, elastomeric stamp is first inked, dried, and then placed over a substrate to localize a chemical reaction between molecules from the ink and the substrate [1]. The printed pattern can lend the substrate various types of properties: protection against etching or corrosion, nucleation of metallization or of crystal growth, selective wetting or adhesion of molecules from a gaseous or liquid phase, for example. All demonstrations and applications of mCP so far used patterned stamps formed by polymerization of an elastomer on a mold. After the stamp is released, it retains the pattern of its mold even after multiple inking and printing steps, although mechanical deformations and swelling can compromise the accuracy of the printed pattern.

     Figure 1 illustrates a plausible strategy for using planar stamps for microcontact printing. The pattern is provided by the inker pad, and the ink is transferred directly from the inker pad to the stamp in the regions of contact, suggesting the term "contact inking" to describe this operation [2]. The stamp becomes a simple receptacle for the ink but still provides conformal contact to both inker pad and substrate by its elastomeric nature. The use of a flat stamp can offer some advantages compared to conventional mCP. First, fabrication of the stamp is easy: curing of its liquid prepolymer components occurs on a flat surface (no mold) from which the stamp can be peeled off without damaging. Second, contact inking a planar stamp separates the pattern-carry function from the conformal-contact function. Third, the surface of a flat stamp is not prone to mechanical deformations and distortions during p...