Direct Electron-Beam Patterning of Teflon AF

Karre, Vijayasree; Keathley, Phillip D.; Guo, Jing; Hastings, J. T.

doi:10.1109/tnano.2009.2013137

Cited by 9 publications

(14 citation statements)

References 11 publications

(12 reference statements)

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“…For the given thickness of the Teflon AF film, exposure doses greater than 1500 μC cm –2 did not cause further changes, neither in trench depth nor in surface potential (data not shown). Note that Karre et al also reported a dependency of trench depths on the total thickness of the Teflon AF film …”

Section: Resultsmentioning

confidence: 91%

“…Note that Karre et al also reported a dependency of trench depths on the total thickness of the Teflon AF film. 48 X-ray photoelectron spectroscopy (XPS) oxygen analysis revealed further clues with respect to the chemical modifications in the polymer following e-beam irradiation. Our experiments show the appearance of a Independently conducted water contact angle measurements on larger areas showed a decrease from 118 to 94°for as-spun and irradiated surfaces, respectively (Supporting Information SI1).…”

Section: Resultsmentioning

confidence: 99%

“…The structural changes in the irradiated film clearly cause a loss of lipophilicity, which we found to be sufficient to hinder the spreading of lipid films, so that selective coverage of the surface by the lipid film is observed. According to Karre et al, electron radiation causes degradation of the polymer by removing some ÀCF 3 groups, 48 which explains to some extent the observed loss of hydrophobicity.…”

Section: Resultsmentioning

confidence: 99%

“…34 To introduce nanosized features into a Teflon AF surface, Karre et al employed electron-beam lithography on thin films of the material and achieved the smallest feature size of 200 nm. 48 This direct e-beam patterning does not form isolated individual structures but causes the formation of trenches with dosedependent depth on the film surface.…”

mentioning

confidence: 99%

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Nanopatterning of Mobile Lipid Monolayers on Electron-Beam-Sculpted Teflon AF Surfaces

Shaali¹,

Lara‐Avila²,

Dommersnes

et al. 2015

ACS Nano

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Direct electron-beam lithography is used to fabricate nanostructured Teflon AF surfaces, which are utilized to pattern surface-supported monolayer phospholipid films with 50 nm lateral feature size. In comparison with unexposed Teflon AF coatings, e-beam-irradiated areas show reduced surface tension and surface potential. For phospholipid monolayer spreading experiments, these areas can be designed to function as barriers that enclose unexposed areas of nanometer dimensions and confine the lipid film within. We show that the effectiveness of the barrier is defined by pattern geometry and radiation dose. This surface preparation technique represents an efficient, yet simple, nanopatterning strategy supporting studies of lipid monolayer behavior in ultraconfined spaces. The generated structures are useful for imaging studies of biomimetic membranes and other specialized surface applications requiring spatially controlled formation of self-assembled, molecularly thin films on optically transparent patterned polymer surfaces with very low autofluorescence.

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Section: Resultsmentioning

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Nanopatterning of Mobile Lipid Monolayers on Electron-Beam-Sculpted Teflon AF Surfaces

Shaali¹,

Lara‐Avila²,

Dommersnes

et al. 2015

ACS Nano

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“…The feature size of such structures can be as low as 1.8 μm, while the gaps between Teflon AF features can be smaller than 1 μm. Only methods involving expensive mask-less irradiation are known to give better pattern resolution of Teflon AF or other fluorocarbon films. − Furthermore, our fabrication technique allows the patterned Teflon AF to be used in small-scale biologically inspired applications. We show that the distinct topographical edge feature of the Teflon AF structures we produce is especially suitable to guide cell growth.…”

Section: Introductionmentioning

confidence: 99%

High-Resolution Micropatterned Teflon AF Substrates for Biocompatible Nanofluidic Devices

et al. 2012

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We describe a general photolithography-based process for the microfabrication of surface-supported Teflon AF structures. Teflon AF patterns primarily benefit from superior optical properties such as very low autofluorescence and a low refractive index. The process ensures that the Teflon AF patterns remain strongly hydrophobic in order to allow rapid lipid monolayer spreading and generates a characteristic edge morphology which assists directed cell growth along the structured surfaces. We provide application examples, demonstrating the well-controlled mixing of lipid films on Teflon AF structures and showing how the patterned surfaces can be used as biocompatible growth-directing substrates for cell culture. Chinese hamster ovary (CHO) cells develop in a guided fashion along the sides of the microstructures, selectively avoiding to grow over the patterned areas.

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Vanishing Hysteresis in Carbon Nanotube Transistors Embedded in Boron Nitride/Polytetrafluoroethylene Heterolayers

Kumar

Dagli

Dehm

et al. 2020

Physica Rapid Research Ltrs

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Carbon nanotube field‐effect transistors fabricated on silicon wafers with thermal oxide often suffer from large gate‐voltage hysteresis, induced by charge trapping sites in oxides, surface hydroxyl groups, and the presence of water molecules. Surface functionalization and passivation, as well as vacuum annealing and reduced operating temperature, have shown to diminish or even eliminate hysteresis. Herein, the fabrication of nearly hysteresis‐free transistors on Si/SiO2 by embedding carbon nanotubes and the connecting electrodes in a hexagonal boron nitride (h‐BN) bottom layer and a polytetrafluoroethylene (PTFE) top layer is demonstrated. The conditions at which catalyst‐free synthesis of h‐BN on SiO2/Si with borazine is obtained, and the subsequent liquid‐phase deposition of PTFE, are discussed. Device transfer curves are measured before and after PTFE deposition. It is found that the hysteresis is reduced after PTFE deposition, but vanishes only after a waiting period of several days. Simultaneously, the on‐state current increases with time. The results give evidence for the absence of trap states in h‐BN/PTFE heterolayers and a high breakthrough field strength in those wafer‐scalable materials.

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Direct Electron-Beam Patterning of Teflon AF

Cited by 9 publications

References 11 publications

Nanopatterning of Mobile Lipid Monolayers on Electron-Beam-Sculpted Teflon AF Surfaces

Nanopatterning of Mobile Lipid Monolayers on Electron-Beam-Sculpted Teflon AF Surfaces

High-Resolution Micropatterned Teflon AF Substrates for Biocompatible Nanofluidic Devices

Vanishing Hysteresis in Carbon Nanotube Transistors Embedded in Boron Nitride/Polytetrafluoroethylene Heterolayers

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