Contrast Studies on Organic Monolayers of Different Molecular Packing in FESEM and Their Correlation with SFM Data

In living organisms the natural contact areas between cells are the cell membranes. These membranes separate the individual cells or build reaction compartments in an aqueous environment. Beside their structural role they also have specific functions that are due to the great variety of their components which are lipids (about 40 %) and proteins (about 60 %).In terms of implant development the next neighbors of the cells are artificial materials which do not belong to the natural cellular environment. Therefore, a biocompatible implant surface is needed which is achieved by either the correct choice of the material and surface roughness or a functionalization of the surface.To date little is known of the role lipids could play in this context. However, from literature we know that phospholipids can cause calcification and that modified phosphorylcholine polymers ('MPC polymers') are used to decrease cell adhesion and to improve blood compatibility. In the last few years it became obvious that the lipid contribution in the membrane is not only important as support for proteins but that the lipid membrane itself can also be a target for drug design and its structure can influence the function of the proteins. We therefore focused our interest on this class of amphiphilic molecules. In this work we present initial observations on the modification of metallic implant surfaces of Ti-6Al-7Nb (in mass percent) by phospholipid multilayers, using contact angle measurements and surface sensitive characterization techniques such as scanning electron microscopy (SEM) and scanning force microscopy (SFM). Preliminary data concerning cell adhesion experiments are also presented.Keywords

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“…In this mode voltage contrast [22] and the molecular packing density [23] have an effect on the image formation.…”

Section: Microscopymentioning

confidence: 95%

Biological Multi‐layer Systems as Implant Surface Modification

Willumeit‐Römer

Feyerabend

Kamusewitz³

et al. 2003

Materialwissenschaft Werkst

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“…Since the thickness of the pristine ODT SAMs on Au is %2.16 nm, [26] it is very likely that the contrast resulted mainly from the variations of packing density, molecular orientation, functional group (or composition), or quantity of adsorbates on the plasmaexposed area. [27][28][29] The secondary electrons from the bottom of the Au layer, i.e., the major emission source, were most probably scattered by the post-treated ODT SAMs on Au, resulting in a relatively dark contrast. Compared to the result obtained with an indium tin oxide conductive glass as the inner electrode, shown in Figure 2b, magnetic field occurred between the permanent magnet inner electrode and ground electrode kept the plasma within the space of patterned cavities without additional diffusion into the surrounding imprinted ODT/Au.…”

Section: Resultsmentioning

confidence: 99%

Rapid Micro‐Scale Patterning of Alkanethiolate Self‐Assembled Monolayers on Au Surface by Atmospheric Micro‐Plasma Stamp

Weng

Hsueh

Liao

et al. 2013

Plasma Processes & Polymers

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A dielectric barrier discharge‐based micro‐plasma stamp is used to transfer a micro‐scale pattern onto ultra‐thin octadecanethiolate (ODT) self‐assembled monolayers chemically adsorbed on Au (111). The results show that the specified pattern was transferred onto ODT/Au with a distortion rate of less than 1% and no significant changes in the imprint dimensions. The adsorbates formed during plasma treatment or exposure to air affected the transfer of patterns. The wet‐etching rate for the washed and patterned ODT/Au surface increased 1.6‐fold compared to that for the unwashed one. The boundary of the underlaying Au pattern with plasma exposure increased ≈3% due to lateral diffusion of the Au etching solution.

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“…[17][18][19][20][21] Here we report an organosilane based fiducial grid fabricated on Al ͑Z =13͒ coated PMMA resist that simultaneously reduces electron scattering and yields a high SNR. Au makes the best interface with the SAM and yields an excellent SNR; however, it is not possible to write high resolution patterns because of minimal penetration and strong scattering of the low energy ͑2 keV͒ primary electrons.…”

Section: Resultsmentioning

confidence: 99%

Amino-propyl-triethoxy-silane on aluminum fiducial grids for spatial-phase-locked electron-beam lithography

Samantaray¹,

Hastings²

2009

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Articles you may be interested inSecondary-electron signal level measurements of self-assembled monolayers for spatial-phase-locked electronbeam lithography J. Vac. Sci. Technol. B 29, 06F308 (2011); 10.1116/1.3646897Deep UV patterning of 3-amino-propyl-triethoxy-silane self-assembled molecular layers on alumina A new fiducial grid suitable for low-energy ͑1-5 keV͒ spatial-phase locked electron-beam lithography ͑SPLEBL͒ has been developed based on an aluminum layer with an organosilane grid pattern. The grids ͑400 nm period͒ were made of two to three layers of 3-amino-propyl-triethoxy-silane ͑APTES͒ that was microcontact printed onto Al coated polymethyl methacrylate ͑PMMA͒. Signal-to-noise ratios ͑SNRs͒ were measured at beam energies ranging from 1 to 5 keV at a dose of 20 C / cm 2 and compared to the SNRs of octadecanethiol ͑ODT͒ based fiducial grids on Au, Ag, and Cu. Although fiducial grids made of ODT on Au provided excellent SNR, Au is not suitable because of poor penetration and strong scattering of the primary electrons. ODT based grids on lower atomic number metal such as Ag or Cu yielded inadequate SNRs. In contrast, APTES-based grids on Al provide SNRs approaching ODT on Au with greatly reduced electron scattering. The authors successfully developed a grid removal process that allows patterns to be resolved in the underlying PMMA. These results represent a key step in the development of low-energy SPLEBL.

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Contrast Studies on Organic Monolayers of Different Molecular Packing in FESEM and Their Correlation with SFM Data

Cited by 28 publications

References 15 publications

Biological Multi‐layer Systems as Implant Surface Modification

Biological Multi‐layer Systems as Implant Surface Modification

Rapid Micro‐Scale Patterning of Alkanethiolate Self‐Assembled Monolayers on Au Surface by Atmospheric Micro‐Plasma Stamp

Amino-propyl-triethoxy-silane on aluminum fiducial grids for spatial-phase-locked electron-beam lithography

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