Microfluidic operations using deformable polymer membranes fabricated by single layer soft lithography

Lab on a Chip ◽  
2005 ◽  
Vol 5 (3) ◽  
pp. 350 ◽  
Author(s):  
Narayan SundararajanAuthors contributed equ ◽  
Dongshin KimCurrent address: Department of B ◽  
Andrew A. Berlin
Keyword(s):  
Soft Lithography ◽  
Polymer Membranes ◽  
Single Layer

Organic Thin Film Transistors Fabricated by a Solution Process Using Direct Patterned Single-Layer Graphene Electrodes

2020 ◽  
Vol 20 (10) ◽  
pp. 6435-6440
Author(s):  
Do-Kyung Kim ◽  
Jae-Hyung Han ◽  
Muhan Choi. ◽  
Jin-Hyuk Bae
Keyword(s):  
Thin Film ◽  
Thin Film Transistors ◽  
Soft Lithography ◽  
Solution Process ◽  
Single Layer ◽  
Organic Thin Film Transistors ◽  
Single Layer Graphene ◽  
Metal Catalyst ◽  
Organic Thin Film ◽  
Layer Graphene

We propose the direct transfer method of single-layer graphene (SLG) from metal catalyst Cu-foil to a polymeric insulator and the direct patterning method of the SLG for electrodes of organic thin-film transistors (OTFTs) without contamination using soft-lithography. Through soft-lithography, SLG can be formed in various patterns relatively easily in comparison with the conventional photolithography method that has multiple complex process steps to make graphene patterns. Furthermore, the 6,13-bis(triisopropylsilylethynyl) pentacene OTFTs are fabricated in solution with SLG source and drain electrodes. As a result, the field-effect mobility of OTFTs based on SLG electrodes was enhanced about 4 times in comparison with that of OTFTs using typical metal electrodes due to the decrease in contact resistance.

Fabrication of Tapered Bio Mimetic Cilia Using Bulk Lithography and Ceramic Mold

2014 ◽  
Author(s):  
Chandrashekar V. Adake ◽  
Parag Bhargava ◽  
Prasanna S. Gandhi ◽  
Bhargava Kashyap
Keyword(s):  
Soft Lithography ◽  
Ceramic Body ◽  
Aqueous Suspension ◽  
Slip Casting ◽  
Single Layer ◽  
Ceramic Mold ◽  
Green Body ◽  
Polydimethyl Siloxane ◽  
Casting Technique ◽  
Negative Impression

This paper presents fabrication of tapered, high aspect ratio bio mimetic cilia from Nickel-polydimethyl siloxane (Ni-PDMS) composite by using bulk lithography technique and ceramic molding. Many research groups suggested fabrication of bio mimetic cilia using various techniques which are based on soft lithography and VLSI techniques. Recently a novel single layer micro fabrication technique known as ‘bulk lithography’ which uses an unconstrained photopolymer has been reported by co-authors. This technique is used to fabricate a polymer cilia pattern (an array of photopolymerised inverted cone profile) and using this pattern a ceramic green body is fabricated by slip casting technique. An aqueous suspension containing sub micron size alumina is used to cast ceramic green body. After casting this cilia pattern makes negative impression of tapered holes on green ceramic body. During sintering of green ceramic body the polymer burns off resulting in ceramic mould with tapered holes imprinted on it. This mold retains shape of a tapered hole though it shrinks in size after sintering. This mold is used further to cast Ni-PDMS composite in the form of cilia structures.

Crystalline order to a resolution of 4.7 A in the sheath of Methanospirilium hungatii: A cross-beta structure

1984 ◽  
Vol 42 ◽  
pp. 214-215
Author(s):  
Murray Stewart ◽  
T.J. Beveridge ◽  
D. Sprott
Keyword(s):  
Cell Wall ◽  
Single Layer ◽  
Uranyl Acetate ◽  
Optical Diffraction ◽  
Tube Axis ◽  
Basic Subunit ◽  
Beta Structure ◽  
Diffraction Patterns ◽  
Protein Treatment ◽  
General Appearance

The archaebacterium Methanospirillum hungatii has a sheath as part of its cell wall which is composed mainly of protein. Treatment with dithiothreitol or NaOH released the intact sheaths and electron micrographs of this material negatively stained with uranyl acetate showed flattened hollow tubes, about 0.5 μm diameter and several microns long, in which the patterns from the top and bottom were superimposed. Single layers, derived from broken tubes, were also seen and were more simply analysed. Figure 1 shows the general appearance of a single layer. There was a faint axial periodicity at 28.5 A, which was stronger at irregular multiples of 28.5 A (3 and 4 times were most common), and fine striations were also seen at about 3° to the tube axis. Low angle electron diffraction patterns (not shown) and optical diffraction patterns (Fig. 2) from these layers showed a complex meridian (as a result of the irregular nature of the repeat along the tube axis) which showed a clear maximum at 28.5 A, consistent with the basic subunit spacing.

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

Characterization of a monolayer graphitic structure

1994 ◽  
Vol 52 ◽  
pp. 760-761
Author(s):  
X. Lin ◽  
X. K. Wang ◽  
V. P. Dravid ◽  
J. B. Ketterson ◽  
R. P. H. Chang
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Synthesis Process ◽  
Graphitic Structure ◽  
Positive Gaussian Curvature ◽  
Graphitic Sheet ◽  
Structural And Electronic Properties ◽  
New Material ◽  
Hexagonal Network

For small curvatures of a graphitic sheet, carbon atoms can maintain their preferred sp2 bonding while allowing the sheet to have various three-dimensional geometries, which may have exotic structural and electronic properties. In addition the fivefold rings will lead to a positive Gaussian curvature in the hexagonal network, and the sevenfold rings cause a negative one. By combining these sevenfold and fivefold rings with sixfold rings, it is possible to construct complicated carbon sp2 networks. Because it is much easier to introduce pentagons and heptagons into the single-layer hexagonal network than into the multilayer network, the complicated morphologies would be more common in the single-layer graphite structures. In this contribution, we report the observation and characterization of a new material of monolayer graphitic structure by electron diffraction, HREM, EELS.The synthesis process used in this study is reported early. We utilized a composite anode of graphite and copper for arc evaporation in helium.

The Continuous Single-Layer Anastomosis in the Gastrointestinal Tract

Swiss Surgery ◽  
2003 ◽  
Vol 9 (3) ◽  
pp. 114-120 ◽  
Author(s):  
Steinke ◽  
Leippold ◽  
Schweizer
Keyword(s):  
Gastrointestinal Tract ◽  
Single Layer

Über die Frage der besten oder "richtigen" Technik bei gastrointestinalen Anastomosen wird seit je diskutiert. Die Ansprüche an eine gute Anastomosentechnik sind: Gute Durchblutung, Wasserdichtigkeit, Spannungsfreiheit, Sicherheit, leichte Durchführbarkeit, wenig Unruhe und Verschmutzung im Operationsgebiet und geringe Kosten. Die Operationstechnik der extramukösen, fortlaufenden Anastomosentechnik im Gastrointestinaltrakt wird in Wort und Bild erläutert. Anhand einer Pilotstudie, einer randomisierten Vergleichsstudie, einer Schweizer Multizenterstudie und schliesslich einer 5-jährigen Qualitätskontrollstudie wird gezeigt, dass diese "Schweizer"-Technik allen Anforderungen zur Durchführung einer "idealen" Anastomose gerecht wird und an fast allen intestinalen Lokalisationen verwendet werden kann.

Technical textiles for protection against Arc-flash fire: Savesplash®

2020 ◽  
pp. 67-78
Author(s):  
Nandan Kumar ◽  
Sainath Shrikant Pawaskar
Keyword(s):  
Attenuation Factor ◽  
Threshold Energy ◽  
Single Layer ◽  
Weather Conditions ◽  
Electric Arc ◽  
Risk Category ◽  
Technical Textiles ◽  
Flash Fire ◽  
Level 3 ◽  
Arc Flash

Flash fire caused by electric arc is different than that caused by flammable liquids/fumes or combustible dusts. A suitable protective clothing for protection against electric arc-flash must be designed as per Indian weather conditions. Currently available garments are manufactured using two or three layers of woven/nonwoven combinations to achieve higher Hazard Risk Category (HRC) rating (level 3 and above). However, they are heavy and not comfortable to the end users. Savesplash® is a single layer inherent flame-retardant knitted fabric. Its arc rating was determined using ASTM standards. It achieved arc thermal performance value (ATPV) of 41 cal/cm2, breakopen threshold energy (E_BT) of 42 cal/cm2 and heat attenuation factor (HAF) of 94% when tested as per ASTM F1959/F1959M-14 which translated into an arc rating of 41 cal/cm2. This is equivalent to HRC level 4 ratings as per National Fire Protection Association’s NFPA 70E standard (USA). Further, cut and sewn gloves (HM-100) developed using Savesplash® fabric reinforced with leather on palm area achieved ATPV of 63 cal/cm2 and HAF of 94.5% when tested as per ASTM F2675/F2675M-13.

Discrete element method to model cracking for two layer systems

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 101-108
Author(s):  
Daniel Varney ◽  
Douglas Bousfield
Keyword(s):  
Discrete Element Method ◽  
Flexural Modulus ◽  
Single Layer ◽  
Discrete Element ◽  
Flexural Stress ◽  
Layer System ◽  
Three Point Bending ◽  
Moving Force ◽  
Coating Layers ◽  
Element Method

Cracking at the fold is a serious issue for many grades of coated paper and coated board. Some recent work has suggested methods to minimize this problem by using two or more coating layers of different properties. A discrete element method (DEM) has been used to model deformation events for single layer coating systems such as in-plain and out-of-plain tension, three-point bending, and a novel moving force picking simulation, but nothing has been reported related to multiple coating layers. In this paper, a DEM model has been expanded to predict the three-point bending response of a two-layer system. The main factors evaluated include the use of different binder systems in each layer and the ratio of the bottom and top layer weights. As in the past, the properties of the binder and the binder concentration are input parameters. The model can predict crack formation that is a function of these two sets of factors. In addition, the model can predict the flexural modulus, the maximum flexural stress, and the strain-at-failure. The predictions are qualitatively compared with experimental results reported in the literature.

Cracking at the fold in double layer coated paper: the influence of latex and starch composition

TAPPI Journal ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 93-99
Author(s):  
SEYYED MOHAMMAD HASHEMI NAJAFI ◽  
DOUGLAS BOUSFIELD, ◽  
MEHDI TAJVIDI
Keyword(s):  
Mechanical Properties ◽  
Double Layer ◽  
Starch Content ◽  
Single Layer ◽  
Double Layers ◽  
Coated Paper ◽  
Coated Papers ◽  
Coating Layers ◽  
Scanned Images ◽  
Packaging Paper

Cracking at the fold of publication and packaging paper grades is a serious problem that can lead to rejection of product. Recent work has revealed some basic mechanisms and the influence of various parameters on the extent of crack area, but no studies are reported using coating layers with known mechanical properties, especially for double-coated systems. In this study, coating layers with different and known mechanical properties were used to characterize crack formation during folding. The coating formulations were applied on two different basis weight papers, and the coated papers were folded. The binder systems in these formulations were different combinations of a styrene-butadiene latex and mixtures of latex and starch for two different pigment volume concentrations (PVC). Both types of papers were coated with single and double layers. The folded area was scanned with a high-resolution scanner while the samples were kept at their folded angle. The scanned images were analyzed within a constant area. The crack areas were reported for different types of papers, binder system and PVC values. As PVC, starch content, and paper basis weight increased, the crack area increased. Double layer coated papers with high PVC and high starch content at the top layer had more cracks in comparison with a single layer coated paper, but when the PVC of the top layer was low, cracking area decreased. No measurable cracking was observed when the top layer was formulated with a 100% latex layer.

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