scholarly journals Graphene-electrode array for brain map remodeling of the cortical surface

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Minseok Lee ◽  
Sangwon Lee ◽  
Jejung Kim ◽  
Jeongsik Lim ◽  
Jinho Lee ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Electrode Array ◽  
Chemical Vapor ◽  
Cognitive Status ◽  
Cortical Surface ◽  
Neural Signals ◽  
Spatiotemporal Resolution ◽  
Efficient Manner ◽  
Cortical Maps ◽  
Grown Graphene

AbstractCortical maps, which are indicative of cognitive status, are shaped by the organism’s experience. Previous mapping tools, such as penetrating electrodes and imaging techniques, are limited in their ability to be used to assess high-resolution brain maps largely owing to their invasiveness and poor spatiotemporal resolution, respectively. In this study, we developed a flexible graphene-based multichannel electrode array for electrocorticography (ECoG) recording, which enabled us to assess cortical maps in a time- and labor-efficient manner. The flexible electrode array, formed by chemical vapor deposition (CVD)-grown graphene, provided low impedance and electrical noise because a good interface between the graphene and brain tissue was created, which improved the detectability of neural signals. Furthermore, cortical map remodeling was induced upon electrical stimulation at the cortical surface through a subset of graphene spots. This result demonstrated the macroscale plasticity of cortical maps, suggesting perceptual enhancement via electrical rehabilitation at the cortical surface.

Growth of hematite on (0001) and {1102} sapphire substrates

1990 ◽  
Vol 48 (4) ◽  
pp. 376-377
Author(s):  
Lisa A. Tietz ◽  
Scott R. Summerfelt ◽  
C. Barry Carter
Keyword(s):  
Imaging Techniques ◽  
Chemical Vapor ◽  
Interface Energy ◽  
Dark Field ◽  
Cation Sublattice ◽  
Sapphire Substrates ◽  
Dark Field Imaging ◽  
Weak Beam ◽  
Pressure Chemical ◽  
Interface Structures

Defects in thin films are often introduced at the substrate-film interface during the early stages of growth. The interface structures of semiconductor heterojunctions have been extensively studied because of the electrical activity of defects in these materials. Much less attention has been paid to the structure of oxide-oxide heterojunctions. In this study, the structures of the interfaces formed between hematite (α-Fe2O3) and two orientations of sapphire (α-Al2O3) are examined in relationship to the defects introduced into the hematite film. In such heterojunctions, the oxygen sublattice is expected to have a strong influence on the epitaxy; however, defects which involve only the cation sublattice may be introduced at the interface with little increase in interface energy.Oxide heterojunctions were produced by depositing small quantities of hematite directly onto electrontransparent sapphire substrates using low-pressure chemical vapor deposition. Prior to deposition, the ionthinned substrates were chemically cleaned and annealed at 1400°C to give “clean”, crystalline surfaces. Hematite was formed by the reaction of FeCl3 vapor with water vapor at 1150°C and 1-2 Torr. The growth of the hematite and the interface structures formed on (0001) and {102} substrates have been studied by bright-field, strong- and weak-beam dark-field imaging techniques.

Flexible and Transparent Dielectric Film with a High Dielectric Constant Using Chemical Vapor Deposition-Grown Graphene Interlayer

ACS Nano ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. 269-274 ◽  
Author(s):  
Jin-Young Kim ◽  
Jongho Lee ◽  
Wi Hyoung Lee ◽  
Iskandar N. Kholmanov ◽  
Ji Won Suk ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
High Dielectric Constant ◽  
Dielectric Film ◽  
Chemical Vapor ◽  
Transparent Dielectric ◽  
Grown Graphene ◽  
High Dielectric

The Effects of Hydrogen Flowrate during Pre-Annealing on Graphene Growth by Chemical Vapor Deposition Using Methanol as a Liquid Carbon Precursor

2019 ◽  
Vol 290 ◽  
pp. 107-112
Author(s):  
Raed Abdalrheem ◽  
Fong Kwong Yam ◽  
Abdul Razak Ibrahim ◽  
Khi Poay Beh ◽  
Hwee San Lim ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Light Transmittance ◽  
High Hydrogen ◽  
Flow Rates ◽  
Hydrogen Flow ◽  
Number Of Layers ◽  
Crystallite Sizes ◽  
Grown Graphene

Studying an influence of several parameters on Chemical Vapor Deposition (CVD) used for graphene synthesis is crucial to optimizing the graphene quality to be Compatible with advanced devices. The effect of different hydrogen (H2) flow-rates (0, 50, 100, 150, 200, 250, and 300 sccm) during the pre-annealing process on CVD grown graphene have been reported. This study revealed that hydrogen flow rates during annealing changed the surface roughness/smoothness of the copper substrates. For high hydrogen flow rates, the smoothing effect was increased. Furthermore, the annealed graphene samples emerged a deferent number of layers because of morphological surface changes. According to Raman D- to G-band intensity ratios (ID/IG), the graphene quality was influenced by the annealing hydrogen flowrate. The visible light transmittance values of the grown graphene samples confirmed a few number of layers (mono to seven-layer). Mostly, the samples which annealed under moderate hydrogen flow rates showed less defects intensities and higher crystallite sizes.

scholarly journals Large scale structures in chemical vapor deposition-grown graphene on Ni thin films

2020 ◽  
Vol 709 ◽  
pp. 138225
Author(s):  
Derya Ataç ◽  
Johnny G.M. Sanderink ◽  
Sachin Kinge ◽  
Dirk J. Gravesteijn ◽  
Alexey Y. Kovalgin ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Large Scale ◽  
Chemical Vapor ◽  
Large Scale Structures ◽  
Scale Structures ◽  
Grown Graphene

scholarly journals Vapor deposition routes to conformal polymer thin films

2017 ◽  
Vol 8 ◽  
pp. 723-735 ◽  
Author(s):  
Priya Moni ◽  
Ahmed Al-Obeidi ◽  
Karen K Gleason
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Sample Preparation ◽  
Vapor Phase ◽  
Vapor Deposition ◽  
Imaging Techniques ◽  
Polymer Thin Films ◽  
Chemical Vapor ◽  
Short Review ◽  
Deposition Sample

Vapor phase syntheses, including parylene chemical vapor deposition (CVD) and initiated CVD, enable the deposition of conformal polymer thin films to benefit a diverse array of applications. This short review for nanotechnologists, including those new to vapor deposition methods, covers the basic theory in designing a conformal polymer film vapor deposition, sample preparation and imaging techniques to assess film conformality, and several applications that have benefited from vapor deposited, conformal polymer thin films.

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