Cell Self Assembly of Intracellular Interface Using Cell Migration

AbstractA cell-driven self-assembly of intracellular nano-device was proposed for bio-hybrid interface. This cells-driven self-assembly employed cell migration force to insert a conductive nanoneedle which would be worked as intracellular electrode. Such a nanoneedle was fabricated in the bottom of a microwell using focused ion beam induce deposition. The microwell structure with a coating of cell adhesion molecules was employed as the scaffold of the cell migration. A glass plate with the microwells had a non cell binding coating of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer as an anti-biofouling material. Thus a cell adhered only on the wall of a microwell then the cell migrated into the microwell. Adhesion force and migration force induced self-insertion of the nanoneedle into a live cell body using the cell's own migration force. The inserted nanoneedle was made of electrical conductive tungsten, so the intracellular nanoneedle might extract intracellular potential more precisely than extracellular electrode, while inducing much less damage to cells. In the future, the technique of cell-driven self-insertion of nanoneedle may be integrated with multi electrode arrays for developing long-lasting measurements device on cellular network researches, or the risk assessment of the nanomaterials on cellular activities.

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Temperature Measurement by Using Metal Thin Film Thermocouples

2003 International Electronic Packaging Technical Conference and Exhibition, Volume 2 ◽

10.1115/ipack2003-35042 ◽

2003 ◽

Cited By ~ 1

Author(s):

Koji Miyazaki ◽

Hiroshi Tsukamoto ◽

Takahiro Miike ◽

Toshiaki Takamiya

Keyword(s):

Thin Film ◽

Focused Ion Beam ◽

Ion Beam ◽

Glass Plate ◽

Mean Free Path ◽

Dimensional Structure ◽

Measured Temperature ◽

Metal Thin Film ◽

Thin Film Thermocouples ◽

Thermocouple Junction

We fabricate metal thin film thermocouples (TFTCs). Au-Pt, Cu-Ni, and W-Ni are deposited on a glass plate using standard thin film processes. The dimension of thermocouple junction is 300μm × 300μm. The thermoelectric powers of TFTCs are different from those of bulk because diffusion of electrons is restricted by the very thin film. The film thickness of TFTCs is of the same order as the mean free path of electrons. However TFTCs are still useful for temperature measurements because the thermoelectric voltage is proportional to measured temperature at thermocouple junction. The response time of Au-Pt TFTCs is about 30ns when the surface of the glass is heated by a YAG pulsed laser. The result compares favorably with measurements by a thermoreflectance method. We also describe W-Ni nano-TFTCs fabricated by Focused Ion Beam for the measurement of temperature distribution in a sub-micron area. In order to reduce the size of the TFTCs we employ a 3-dimensional structure.

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Guided Control of Cu2O Nanodot Self-Assembly on SrTiO3 (100)

MRS Proceedings ◽

10.1557/proc-811-e4.4 ◽

2004 ◽

Vol 811 ◽

Author(s):

Yingge Du ◽

Surajit Atha ◽

Robert Hull ◽

James F. Groves ◽

Igor Lyubinetsky ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Self Assembly ◽

Focused Ion Beam ◽

Ion Beam ◽

Photocatalytic Decomposition ◽

Process Conditions ◽

Photochemical Process ◽

Force Microscopy ◽

Atomic Force

ABSTRACTA method has been developed for specifying the growth location of Cu2O nanodotson SrTiO3 (100) substrates. Growth location has been specified by using a focused ion beam (FIB) to modify microscopic and nanoscopic regions of the SrTiO3substrate prior to Cu2O deposition. Deposition onto the modified regions under carefully selected process conditions has generated nanodot growth at the edge of microscopic FIB-induced features and on top of nanoscopic FIB-induced features. For this work, an array of evenly spaced FIB implants was first patterned into several regions of each substrate. Within each sub-division of the array, the FIB implants were identical in Ga+ energy and dosage and implant diameter and spacing. After FIB surface modification and subsequent in-situ substrate cleaning, Cu2O nanodots were synthesized on the patterned SrTiO3 substrates using oxygen plasma assisted molecular beam epitaxy. The substrates and nanodots were characterized using atomic force microscopy at various stages of the process; in-situ X-ray photoelectron spectroscopy and Auger electron spectroscopy analysis demonstrated that the final stoichiometry of the nanodots was Cu2O. The photocatalytic decomposition of water on Cu2O under visible light irradiation has been reported. If the Cu2O can be located in the form ofislands on a carefully selected substrate, then it could be possible to greatly enhance the efficiency of the photochemical process.

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Surface Modification Energized by FIB: The Influence of Etch Rates & Aspect Ratio on Ripple Wavelengths

MRS Proceedings ◽

10.1557/proc-0960-n10-02-ll06-02 ◽

2006 ◽

Vol 960 ◽

Cited By ~ 3

Author(s):

Warren MoberlyChan

Keyword(s):

Aspect Ratio ◽

Self Assembly ◽

Focused Ion Beam ◽

Process Development ◽

Ion Beam ◽

Natural Diamond ◽

Single Crystal Silicon ◽

Nanometer Scale ◽

Crystal Silicon ◽

Etch Rates

ABSTRACTIon beams have been used to modify surface topography, producing nanometer-scale modulations (and even subnanometer ripples in this work) that have potential uses ranging from designing self-assembly structures, to controlling stiction of micromachined surfaces, to providing imprint templates for patterned media. Modern computer-controlled Focused Ion Beam tools enable alternating submicron patterned zones of such ion-eroded surfaces, as well as dramatically increasing the rate of ion beam processing. The DualBeam FIB/SEM also expedites process development while minimizing the use of materials that may be precious (Diamond) and/or produce hazardous byproducts (Beryllium). A FIB engineer can prototype a 3-by-3-by-3 matrix of variables in tens of minutes and consume as little as zeptoliters of material; whereas traditional ion beam processing would require tens of days and tens of precious wafers. Saturation wavelengths have been reported for ripples on materials such as single crystal silicon or diamond (∼200nm); however this work achieves wavelengths >400nm on natural diamond. Conversely, Be can provide a stable and ordered 2-dimensional array of <40nm periodicity. Also ripples <0.4nm are fabricated on carbon-base surfaces, and these quantized picostructures are measured by HR-TEM and electron diffraction. Rippling is a function of material, ion beam, and angle; but is also controlled by chemical environment, redeposition, and aspect ratio. Ideally a material has a constant yield (atoms sputtered off per incident ion); however, pragmatic FIB processes, coupled with the direct metrological feedback in a DualBeam tool, reveal etch rates do not remain constant for nanometer-scale processing. Control of rippling requires controlled metrology, and robust software tools are developed to enhance metrology. In situ monitoring of the influence of aspect ratio and redeposition at the micron scale correlates to the rippling fundamentals that occur at the nanometer scale and are controlled by the boundary conditions of FIB processing.

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Focused-ion-beam directed self-assembly of Cu2O islands on SrTiO3(100)

Applied Physics Letters ◽

10.1063/1.1765212 ◽

2004 ◽

Vol 84 (25) ◽

pp. 5213-5215 ◽

Cited By ~ 31

Author(s):

Y. Du ◽

S. Atha ◽

R. Hull ◽

J. F. Groves ◽

I. Lyubinetsky ◽

...

Keyword(s):

Self Assembly ◽

Focused Ion Beam ◽

Ion Beam

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Structure and function of a bacterial gap junction analog

10.1101/462465 ◽

2018 ◽

Cited By ~ 1

Author(s):

Gregor L. Weiss ◽

Ann-Katrin Kieninger ◽

Iris Maldener ◽

Karl Forchhammer ◽

Martin Pilhofer

Keyword(s):

Intercellular Communication ◽

Focused Ion Beam ◽

Ion Beam ◽

Cell Junction ◽

Domains Of Life ◽

A Cell ◽

Electron Cryotomography ◽

And Function ◽

Sister Cells

SummaryMulticellular lifestyle requires cell-cell connections. In multicellular cyanobacteria, septal junctions enable molecular exchange between sister cells and are required for cellular differentiation. The structure of septal junctions is poorly understood and it is unknown whether they regulate intercellular communication.Here we resolved thein situarchitecture of septal junctions by electron cryotomography of cryo-focused ion beam-milled cyanobacteria. Septal junctions consisted of a tube traversing the septal peptidoglycan. Each tube end comprised a plug that was covered by a cytoplasmic cap. Fluorescence recovery after photobleaching showed that intercellular communication was blocked upon stress. This gating was accompanied by a conformational change of the septal junctions, mediated by the proteins FraC/D.We provide the mechanistic framework for a cell junction that predates eukaryotic gap junctions by a billion years. The conservation of a gated dynamic mechanism across different domains of life emphasizes the importance of controlling molecular exchange, e.g. upon injury.

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Ge Nanodroplets Self-Assembly on Focused Ion Beam Patterned Substrates

Nano Science and Technolgy - Lateral Aligment of Epitaxial Quantum Dots ◽

10.1007/978-3-540-46936-0_15 ◽

2007 ◽

pp. 429-440

Keyword(s):

Self Assembly ◽

Focused Ion Beam ◽

Ion Beam ◽

Patterned Substrates

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Heteroepitaxial Self-Assembly of Higher-Complexity Structures By Combining Growth Control with Nanopatterning

MRS Proceedings ◽

10.1557/proc-849-kk4.3 ◽

2004 ◽

Vol 849 ◽

Author(s):

Jerrold A. Floro ◽

Jennifer L. Gray ◽

Surajit Atha ◽

Nitin Singh ◽

Dana Elzey ◽

...

Keyword(s):

Quantum Dot ◽

Self Assembly ◽

Focused Ion Beam ◽

Ion Beam ◽

Three Dimensional ◽

Growth Control ◽

Additional Degree ◽

Quantum Dot Molecules ◽

Symmetric Quantum ◽

Dimensional Growth

ABSTRACTWe provide an overview of a novel self-assembly process that occurrs during GeSi/Si(001) strain-layer heteroepitaxy under conditions of limited adatom mobility. Suppression of copious surface diffusion leads to limited three-dimensional roughening in the form of pits that partially consume a thick, metastable wetting layer. The material ejected from the pits accumulates alongside, eventually forming a symmetric quantum dot molecule consisting of four islands bound to a {105}-faceted pit. These structures, which are of interest in nanologic applications, appear to arise from an intrinsic strain-relief mechanism in a relatively narrow regime of deposition conditions. An additional degree of morphological control is obtained by annealing films containing pits, before they evolve to full quantum dot molecules. Annealing promotes a one-dimensional growth instability leading to the formation of highly anisotropic grooves, bounded by long, wire-like islands. Finally, we show that patterns created in the Si substrate using a focused ion beam can control the location of quantum dot molecules, which is an additional critical step towards being able to use these structures for computing.

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