Soft-lithography

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Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles

Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles

Here, we report a straightforward procedure to obtain hierarchical structures on soft poly(dimethylsiloxane) (PDMS) films by lift-up soft-lithography and post-decoration with Ag nanoparticles (NPs) to render the superhydrophobic surfaces. During the past decade, soft-lithography has been well developed as a new micro-fabrication method to prepare various patterned surfaces by using elastomeric stamps, molds and masks. Compared with other approaches, soft-lithography is relatively inexpensive with simple procedures and does not demand special instruments [ 33 ]. Obviously, the reported approach is low-cost and easy to handle. The advantages of our soft superhydrophobic films are appreciable: (i) they can be reused, and hence minimize material waste; (ii) various smooth surfaces can become superhydrophobic via ready coating with these films, especially for those hydrophilic materials which can hardly exhibit superhydrophobicity.
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Sub-Micrometer Patterning Using Soft Lithography

Sub-Micrometer Patterning Using Soft Lithography

approaches have a different emphasis of patterning, they collectively rely on the rubber0elastic properties of the polymer to achieve intimate, yet reversible contact with another surface, substrate or material. This characteristic feature then eventually helped conceive the term soft lithography in 1996 [ 9 ]. By current standards, however, the meaning of soft goes beyond the original nomenclature since this predicate can equally be applied to most of the materials that are to be patterned. In many cases, these are organic compounds (e.g., self0assembling molecules or polymers), biological species (e.g., proteins and cells) and, to some extent, thin metallic films, which are soft in the true sense of the word. Perhaps, properties such as sensitive or fragile are equally emphasized, but in a rather metaphorical manner. Moreover, soft patterning techniques generally proceed at relatively mild conditions, where high temperatures, extreme pressures or exposure to aggressive chemicals are commonly avoided. Here, soft may represent a synonym of this quality similar to as gentle or friendly would possibly be. There is no doubt that soft lithography enjoyed a great deal of popularity over the course of the past decade, and what once had been started by a handful of people at Harvard University has evolved into an enterprise of global dimension. With research in this field traditionally being strong in the United States, there is now an increasing presence of players in Europe and throughout Asia. The open literature also suggests that soft lithography has attracted interest across a broad range of
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Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles

Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles

Supporting Information Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles Tongjie Yao 1 , Chuanxi Wang 1 , Quan Lin 1 , Xiao Li 1 , Xiaolu Chen 1 , Jie Wu 1 , Junhu Zhang 1 , Kui Yu 2 and Bai Yang 1 *

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Computer-Aided Design for Microfluidic Chips Based on Multilayer Soft Lithography

Computer-Aided Design for Microfluidic Chips Based on Multilayer Soft Lithography

As a first step towards this vision, in this paper we address the problem of generating the control layer on a microfluidic chip. As depicted in Figure 1, a chip manufactured with multilayer soft lithography consists of two layers: a flow layer and a control layer. Channels on the flow layer carry the biological fluids of interest, while channels on the control layer are connected to external pressure actuators. Designing the control layer requires three steps: 1) placing valves on top of the flow layer, which restrict fluid flow upon being pressurized; valve placement depends on the flow patterns that are required by the biology experiment, 2) placing control ports on the periphery of the chip, where external pressure actuators are inserted, and 3) routing each valve to a control port, via a control channel. The control layer is one of the most tedious aspects for designers today, as it requires careful reasoning and also needs to be repeated for every change to the flow topology or logical chip operation. The control layer is also a good target for automation, as it is subject to a well-defined set of design rules.
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Automation of soft lithography

Automation of soft lithography

Patterned SAMs on a stamp is formed by contacting inked stamp with a substrate for a few seconds. And the relief patterns of a PDMS stamp transports ink on the substrates by c[r]

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Design and prototype : a manufacturing system for the soft lithography technique

Design and prototype : a manufacturing system for the soft lithography technique

Excess material may potentially cause the air-trapping in the work piece in the later stage when the stamp is placed on the substrate while material insufficiency will lead to [r]

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Contact region fidelity, sensitivity, and control in roll-based soft lithography

Contact region fidelity, sensitivity, and control in roll-based soft lithography

Using this new stamp architecture, large features can be introduced at the roll interface to tune the mechanical response of the stamp even when very small featur[r]

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Legitimate domain of a Newtonian behavior for thermal nanoimprint lithography

Legitimate domain of a Newtonian behavior for thermal nanoimprint lithography

3. Critical area to be excluded and shear rate normalization The addressed problem is similar to the indentation of a rigid flat base punch with sharp square corners into a soft incompressible elastic surface [12], by interpreting the displacement field as a velocity field and the shear modulus as a viscosity. It has been shown that pressure and shear stress reach infinite values under the corners in such a problem [12]. These singu- larities are also demonstrated in numerical simulations, where the thinner the mesh is, the higher the maximal computed values of pressure and shear rate are under the corners. These infinite values illustrate the limits of a linear behavior to describe this indentation problem. Consequently, shear-thinning is expected in these regions for real materials, even at the lightest load. In this case we can nevertheless expect the shear-thinning effects to be limited to a small volume fraction of the polymer, with small consequences on the results elsewhere. Therefore, the solution calculated with a Newtonian be- havior everywhere is assumed to be valid except in the vicinity of the pattern corners, and we define a critical area as a disc centered on the corner with a radius ε, as presented in figure 1. The shear rate will be studied outside this area and is expected to reach a maximum on the disc boundary. The radius will be compared to the width L of the pattern in order to give an estimation of the validity of the Newtonian solution. The ratio ε/L defines the fraction of polymer where shear-thinning is likely to appear, and its value depends on the accuracy needed for the solution. In this paper we use a ε/L ratio of 4%. An optimum value could be determined by matching simulations with experimental results.
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Legitimate domain of a Newtonian behavior for thermal nanoimprint lithography

Legitimate domain of a Newtonian behavior for thermal nanoimprint lithography

Keywords: Imprint simulation, Newtonian behavior, Shear-thinning 1. Introduction Nanoimprint lithography (NIL) is a process where nanometric patterns are engraved into a very thin polymer film. In the variant considered here, thermal nanoimprint, the polymer is spin coated on a silicon wafer before imprint at temperature above the glass transition temperature. The surfaces involved are of the order of hundreds of square centimeters to allow for the simultaneous imprint of a very large number of patterns. Although thermal

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Hyper high NA achromatic interferometer for immersion lithography at 193nm

Hyper high NA achromatic interferometer for immersion lithography at 193nm

corresponds to field sizes of respectively 90, 42 and 32 µm which is too small to be used in practice. Since researchers have focused on the study of immersion lithography at 193 nm, several setups have been built around the world. They have been faced those laser limitations, hence the optical components have to be adapted to obtain high-contrast-fringes. This has been achieved by either playing on the laser [3, 4] with the use of solid or frequency-doubled laser or on the optical setup with the design of a high-precision compact Talbot prism lens [5]. Unfortunately such setups are not without disadvantages since they require expensive lasers and optical components difficult to fabricate. We have built up a setup that has the main advantage to be achromatic: thus, temporal coherence is irrelevant and spatial coherence limits only the depth-of-focus within which interference can be obtained. Therefore it is possible to use a basic commercial ArF excimer laser as the exposure source. The other advantage of this interferometer is that the main optical elements, namely the two diffraction gratings, are fabricated using the capabilities of the silicon line available in our laboratory. Therefore, because of the simplicity and ease of fabrication of the basic optical elements of the setup, we are free to switch to various applications such as high index fluids testing and contact holes printing in a very simple way.
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Process modeling for proximity effect correction in electron beam lithography

Process modeling for proximity effect correction in electron beam lithography

7 Abstract Since the development of the first integrated circuit, the number of components fabricated in a chip continued to grow while the dimensions of each component continued to be reduced. For each new technology node proposed, the fabrication process had to cope with the increasing complexity of its scaling down. The lithography step is one of the most critical for miniaturization due to the tightened requirements in both precision and accuracy of the pattern dimension printed into the wafer. Current mass production lithography technique is optical lithography. This technology is facing its resolution limits and the industry is looking for new approaches, such as Multi-patterning (MP), EUV lithography, Direct Write (DW), Nanoimprint or Direct Self-Assembly (DSA). Although these alternatives present significant differences among each other, they all present something in common: they rely on e-beam writers at some point of their flow.
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Modeling soft granular materials

Modeling soft granular materials

5 Conclusion In this paper, we used two methods developed for the com- paction of a packing of soft grains beyond the random close packing. The bonded particle model (BPM) is based on the representation of the grains as aggregates of rigid grains interacting via a hard-particle repulsive force at their contact points and an attraction force acting between particle cen- ters up to a cut-off distance above one particle diameter. The material point method (MPM) is based on a discretization of the grains into moving material points. We implemented an implicit formulation of the MPM interfaced with the con- tact dynamics (CD) method for the treatment of frictional contacts. It was shown that, while MPM grains behave elasti- cally by construction, the BPM grains have a perfectly plastic behavior.
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Optimal soft arc consistency

Optimal soft arc consistency

Beyond this practical usefulness, we think that OSAC brings to light the fact that, in order to increase their strength, new soft local consistency algorithms should probably not be restricted to the mechanical application of elementary oper- ations but should instead try to identify worthy set of equiv- alence preserving operations that should be simultaneously applied. If maintaining OSAC during search is an obvious but challenging next step, the construction of simpler limited versions of OSAC should also be considered.

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Soft Textured Shadow Volume

Soft Textured Shadow Volume

tions described in the Depth Complexity Sampling algorithm [ FBP08 ]. The decorrelated sample distributions are gener- ated by randomly rotating per pixel the pre-computed sam- ple positions. According to the desired performance/quality ratio, we propose to distribute either 16 or 64 samples onto the light source. Note that any number of samples can be chosen with respect to hardware limitations. The low-discrepancy sample distribution is based on the (0, 2)- sequence while with the Poisson disk sampling strategy we experimentally fix the minimum distance constraint to 0.2456139 or 0.1076681 for respectively 16 or 64 samples. 4.2. Soft Textured Shadow Volume Extrusion
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Displacement Talbot Lithography for nano-engineering of III-nitride materials

Displacement Talbot Lithography for nano-engineering of III-nitride materials

49 Damilano, B., Vézian, S., Brault, J., Alloing, B. & Massies, J. Selective Area Sublimation: A Simple Top- down Route for GaN-Based Nanowire Fabrication. Nano. Lett. 16, 1863-1868 (2016). 50 Damilano, B. et al. Top-down fabrication of GaN nano-laser arrays by displacement Talbot lithography and

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Chemical force microscopy for hot-embossing lithography release layer characterization

Chemical force microscopy for hot-embossing lithography release layer characterization

for hot embossing lithography. Acknowledgements Some of the preliminary work was performed at the Cornell Nanofabrication Facility (a member of the National Nanofabrication Users Network) which is supported by the National Science Foundation under Grant ECS-9731293, its users, Cornell University and Industrial Affiliates. The authors are also grateful for collaborations with Quantiscript Inc. and Micralyne Inc, which contribute to the context for this study. NSC is particularly grateful for helpful discussions and useful interactions with Prof. L. Cuccia (Concordia University, Montreal), Dr. G. Cross (Trinity College, Dublin), Dr. M. Geissler (NRC) and our reviewers who provided many constructive comments.
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A Theory of Soft Capture

A Theory of Soft Capture

In this paper, we develop a formal model of soft capture in a three- tier hierarchy. Our main result is to show that the principal can tolerate (soft) capture at equilibrium. 10 Regarding this, two conditions should be satisfied. First, the information provided to the principal by the regulator should be soft rather than hard information. If the information is verifiable, any possible bias will be immediately detected and soft capture would not be an issue. This implies that soft capture is more of a concern when the regulator is asked to develop a methodology for conducting regulations (a typical example of soft information) than when it is asked to apply a specific regulation. Second, the information received by the principal should remain sufficiently informative. Without this condition, the principal would no longer maintain a costly intermediate for transmitting pure noise. Messages remain informative either if the firm does not systematically send them or if the regulator does not always accept them. In one of these
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L’évaluation des Soft Skills des Managers de proximité

L’évaluation des Soft Skills des Managers de proximité

A cet effet, nous avons rencontré 22 professionnels des Ressources Humaines, dans des entreprises de taille, de secteur d’activité, de type d’actionnariat et de nationalité différents afin de faire un tour d’horizon de leurs pratiques en la matière. A l’issue de nos entretiens, notre étude montre que le degré de formalisation des dispositifs d’évaluation autour des soft skills des Managers est globalement élevé. Il est également corrélé à la taille, au mode de gestion de l’organisation et dans une moindre mesure, à son secteur d’activité. De plus, l’étude révèle que le degré de formalisation ainsi que les outils d’évaluation et de développement de ces compétences sont liés à la stratégie de l’entreprise. Mais la formalisation des Soft Skills, que ce soit par le biais de référentiels, d’outils d’évaluation et de développement, même très élaborés, ne suffisent pas à appréhender ces dimensions humaines dans leur complexité, leur globalité, leur essence même : les termes utilisés montrent d’ailleurs leurs limites, ainsi que la difficulté à définir ces compétences sans les restreindre à leurs manifestations.
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Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

NRC Publications Archive Archives des publications du CNRC Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Hot Embossing Lithography: Release-Layer Characterization by Chemical Force Microscopy

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Optimization of demolding temperature for throughput improvement of nanoimprint lithography

Optimization of demolding temperature for throughput improvement of nanoimprint lithography

Keywords: Nanoimprint lithography; Patterns reflow; Demolding modelisation; Throughput optimization 1. Introduction The international technology roadmap for semiconduc- tor (ITRS) trends predicts constant diminution of the fea- tures width and improvement of their quality. Whereas wavelength downsizing or immersion techniques are pro- posed to improve capabilities of conventional projection lithographies, other approaches are proposed for next gen- eration lithographies (NGL). Nanoimprint lithographies are emerging as the long-awaited disruptive technologies. Among them, hot embossing lithography appears as the most flexible and low-cost technology. Contrary to UV nanoimprint lithography (UV-NIL), hot embossing lithog- raphy is free from a lot of material issues. The two mains advantages are that resist do not need to be UV curable and quartz stamps are not required. De facto, thermal nanoimprint lithography has achieved great results since Chou et al. has demonstrated imprint feasibility in 1995
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