Retour au site du LAAS-CNRS

Abstract

It is well established that polydimethylsiloxane (PDMS) stamps submitted to an adequate plasma treatment spontaneously develop an ordered surface roughness. In this work, we show that thin layers made of polyamidoamine (PAMAM) dendrimers can be patterned at the nanoscale using these buckled PDMS stamps. The structures accurately reproduce the self-assembled waves observed on the stamp surface after plasma treatment. We discuss the involved transfer of molecules from the stamp to the surface, which relies on molding rather than on printing. Self-assembled networks of lines made of dendrimers with submicrometric pitch can therefore be produced using this process at very low cost without any advanced lithography method for generating hard molds.

Abstract

In this paper we present an alternative approach to transfer-print controlled arrays of sub-100 nm gold nanoparticles onto a substrate with high placement accuracy. First, the assembly of gold nanoparticles is achieved on a topologically nanopatterned polydimethylsiloxane stamp through a convective and capillary assembly technique. Second, the dry particles assembly is subsequently printed from the plate onto plane substrates by contact through a thin film of liquid. We demonstrate that microcontact printing can be performed with solvent mediation for a high precision transfer of sub-100 nm individual particles and we discuss the most appropriate solvent. The transferred particles preserve their organization and physical properties.

Mots-Clés / Keywords

Abstract

Commonly, one of the challenges in the development of todays nanodevices is the integration of nano-objects or molecules onto desired locations on a substrate. This integration comprises their accurate positioning, their alignment and the preservation of their functionality with respect to assembly processes. Required are novel engineering approaches to overcome this problem. Here, we prove how capillary assembly in combination with soft-lithography can be used to perform phage lambda DNA molecular combing to generate chips of isolated DNA strands for genetic analysis and diagnosis. The assembly of DNA molecules was achieved on a topologically micropatterned polydimethylsiloxane (PDMS) stamp inducing almost simultaneously the trapping and stretching of single molecules. The DNA molecules were then transfer printed onto a glass slide coated by vapour deposition of 3-aminopropyltrimethoxysilane (APTMS) molecules. In fact, this technique offers the possibility to tightly control the experimental parameters to direct the assembly process in a highly reproducible manner. We can easily create arrays or more complex networks of stretched DNA molecules with high yield, while preserving their functionality.

Mots-Clés / Keywords

Abstract

We have developed a novel method for multiplexing the Micro-Contact Printing (¼CP) technique which targets the deposition of 1001000 different molecules in one step. For this purpose we have fabricated so-called macrostamps containing millimetric pads arranged in a periodic array compatible with titration plates. Through a very simple procedure of molding, each of this pad includes topographical micro and nanoscale features suitable for ¼CP on its surface. Then by inking the macrostamp in a single step through a titration plate, it becomes possible to print different inks in one step. The validations of this process are presented with the latest results showing that without any trace of contamination up to 800 different biological inks can be printed in one step. This method could be efficiently exploited for generating at low cost new slides for DNA Micro-arrays.

Abstract

We describe an adaptation of the microcontact printing technique for generating self-aligned patterns of two different molecules in one printing step. Elastomeric stamps exhibiting different levels of topography are designed and fabricated so that, by external pressure, their deformation enables two planes, selectively inked with two different molecules, to contact the surface. The fabrication of 1 µm wide biomolecular patterns aligned into 5 µm wide patterns of another biomolecule is demonstrated through fluorescence imaging and atomic force microscopy.