Self-assembling materials spontaneously form structures at length scales of interest in nanotechnology. In the particular case block copolymers, thermodynamic driving forces for self-assembly are small, and low-energy defects can get easily trapped. We directed assembly defect-free arrays isolated copolymer domains densities up to 1 terabit per square inch on chemically patterned surfaces. comparing assembled chemical pattern, density is increased by a factor four, size reduced two,...

The human corneal basement membrane has a rich felt-like surface topography with feature dimensions between 20 nm and 200 nm. On the basis of these findings, we designed lithographically defined substrates to investigate whether nanotopography is relevant stimulus for epithelial cells. We found that cells elongated aligned along patterns grooves ridges as small 70 nm, whereas on smooth substrates, were mostly round. percentage was constant substrate tomographies lateral ranging from nano-...

Self-assembly is an effective strategy for the creation of periodic structures at nanoscale. However, because microelectronic devices use free-form design principles, insertion point self-assembling materials into existing nanomanufacturing processes unclear. We directed ternary blends diblock copolymers and homopolymers that naturally form arrays to assemble nonregular device-oriented on chemically nanopatterned substrates. Redistribution homopolymer facilitates defect-free assembly in...

The glass transition temperatures (Tg's) of ultrathin films (thickness 80−18 nm) polystyrene (PS) and poly(methyl methacrylate) (PMMA) were measured on surfaces with interfacial energies (γSL) ranging from 0.50 to 6.48 mJ/m2. consisted self-assembled octadecyltrichlorosilane (OTS) that exposed X-rays in the presence air. Exposure X-ray radiation systematically modified OTS by incorporating oxygen-containing groups surface. energy for PS PMMA surface was quantified as a function dose using...

Self-assembling block copolymers are of interest for nanomanufacturing due to the ability realize sub-100 nm dimensions, thermodynamic control over size and uniformity density features, inexpensive processing. The insertion point these materials in production integrated circuits, however, is often conceptualized short term niche applications using dense periodic arrays spots or lines that characterize bulk copolymer morphologies, long device layouts completely redesigned into arrays. Here we...

The lithographic process is arguably the key enabling technology for digital age. Hundreds of millions devices can be fabricated on a single chip because patterns with features as small 50 nm written remarkable level perfection, in registration underlying substrate, and complex geometries. As drive to pattern at ever shrinking length scales continues, however, new imaging materials may required meet manufacturing constraints. We highlight some recent advances integrating self-assembling...

Lamellae-forming polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) films, with bulk period L0, were directed to assemble on lithographically nanopatterned surfaces. The chemical pattern was comprised of "guiding" stripes cross-linked polystyrene (X-PS) or poly(methyl (X-PMMA) mats, width W, and interspatial "background" regions a random copolymer brush styrene methyl methacrylate (P(S-r-MMA)). fraction (f) in the varied control chemistry background regions. Ls. After assembly, density...

The glass transition temperature of polystyrene and poly(methyl methacrylate) films on polar nonpolar substrates was measured as a function thickness using thermal probe in contact with polymer film. Using technique called local analysis, heat loss into the film monitored ramped from ambient to temperatures high 200 °C. determined change slope versus plot. Tg silicon oxide decreased by much 25 °C below bulk value for 13 nm thick. same trend observed treated hexamethyldisilizane (HMDS)....

Properties such as the glass transition temperature ( T(g)) and diffusion coefficient of ultrathin polymeric films are shown to depend on dimensions system. In this work, a hard-sphere molecular dynamics methodology has been applied simulate systems. We investigate influence that substrates have behavior thin polymer films; we report evidence suggesting that, depending strength substrate-polymer interactions, for film can be significantly lower or higher than bulk.

The basement membrane possesses a rich 3-dimensional nanoscale topography that provides physical stimulus, which may modulate cell-substratum adhesion. We have investigated the strength of adhesion on topographic features similar scale to native membrane. SV40 human corneal epithelial cells were challenged by well-defined fluid shear, and cell detachment was monitored. created silicon substrata with uniform grooves ridges having pitch dimensions 400-4000 nm using X-ray lithography. F-actin...

Epitaxial assembly of block-copolymer films (see Figure) onto chemically nanopatterned substrates results in arrays nanoscopic domains that are defect-free, oriented, and registered with the underlying substrate. The range dimensions features (or periodicity structures) can be patterned perfection registration strongly depends on interfacial energy between substrate polymer film.

The ability of random copolymer brushes and cross-linked mats to induce the vertical orientation domains in overlying films lamellae- cylinder-forming block copolymers was investigated as a function composition. substrate-modifying layers consisted styrene methyl methacrylate contained either terminal hydroxyl group or third polar comonomer 2-hydroxyethyl (HEMA) for grafting silicon oxide surfaces glycidyl (GMA) cross-linking into mat. Polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA)...

Molecular simulations of a model, deeply quenched polymeric glass show that the elastic moduli become strongly inhomogeneous at length scales comprising several tens monomers; these calculations reveal broad distribution local moduli, with regions negative coexisting within matrix positive moduli. It is shown have same physical meaning as traditionally ascribed to obtained from direct measurements constitutive behaviors macroscopic samples.

We have previously shown that human corneal epithelial cells respond to synthetic topographic features with dimensions similar those found in the native basement membrane. Epithelial integrated inputs from substrate topography and soluble factors culture medium generate alignment responses anisotropies. Human keratocytes are main cellular components of stroma, tissue underlies epithelium. Here we report aligned more strongly than along patterns grooves ridges. On pitches 800 nm larger...

A coarse grain model and a Monte Carlo sampling formalism are proposed for simulations of self-assembly in block copolymer melts nanoparticle−copolymer composites. Our approach relies on particle-based representation the system, it does not invoke saddle point approximation, permits treatment large three-dimensional systems. We provide detailed description methods discuss their relationship to results from self-consistent-field theory single chain mean field simulations. The validity is...