scholarly journals Carbon Fiber on Polyimide Ultra-Microelectrodes

2017 ◽  
Author(s):  
Winthrop F. Gillis ◽  
Charles A. Lissandrello ◽  
Jun Shen ◽  
Ben W. Pearre ◽  
Alket Mertiri ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Small Diameter ◽  
Tissue Response ◽  
Cross Sectional ◽  
Fiber Array ◽  
Neural Recordings ◽  
Direct Laser ◽  
High Density Recording ◽  
Spontaneous Action

AbstractMost preparations for making neural recordings degrade over time and eventually fail due to insertion trauma and reactive tissue response. The magnitudes of these responses are thought to be related to the electrode size (specifically, the cross-sectional area) and the relative stiffness of the electrode material. Carbon fiber ultramicroelectrodes have a much smaller cross-section than traditional electrodes and thus may enable improved longevity of neural recordings in the central and peripheral nervous systems. Only two carbon fiber array designs have been described previously, each with limited channel densities due to limitations of the fabrication processes or interconnect strategies. Here, we describe a method for assembling carbon fiber electrodes on a flexible polyimide substrate that will facilitate the construction of high-density recording and stimulating arrays for acute use in peripheral nerves. Fibers were aligned using an alignment tool that was 3D-printed with sub-micron resolution using direct laser writing. Indium deposition on the carbon fibers provided a robust and reliable method of electrical connection to the polyimide traces. Spontaneous action potentials and stimulation-evoked compound responses with SNR > 10 and > 120, respectively, were recorded from a small (125 μm) peripheral nerve. We also improved the typically poor charge injection capacity of small diameter carbon fibers can be improved by electrodepositing 100 nm thick iridium oxide films, making the carbon fiber arrays suitable for electrical stimulation as well as recording.

scholarly journals Mechanical Properties of Thermoplastic Composites Made of Commingled Carbon Fiber / Nylon Fiber

2021 ◽  
Author(s):  
Mizuki Ono ◽  
Masachika Yamane ◽  
Shuichi Tanoue ◽  
Yoshihiro Yamashita ◽  
Hideyuki Uematsu
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Fracture Strain ◽  
Flexural Modulus ◽  
Thermoplastic Composites ◽  
Molding Pressure ◽  
Tensile Fracture ◽  
Cross Sectional ◽  
Resin Impregnation ◽  
Commingled Yarns

Fiber-opening treatment of commingled yarns consisting of thermoplastic nylon fibers and carbon fibers could produce superior CFRTP, but few studies toward that end have been conducted. In this study, we investigated whether an open weave fabric consisting of commingled yarns made of carbon and nylon fibers could shorten the impregnation distance of resin to carbon fibers, and there are few reports on the design of fabrics by opening carbon fiber bundles consisting of commingled yarns. From this study, following are cleared. The impregnation speed of the nylon resin on the carbon fiber was very fast, less than 1 minute. As the molding time increased, the tensile strength and tensile fracture strain slightly decreased and the nylon resin deteriorated. The effects of molding time on flexural strength, flexural modulus, and flexural fracture strain were negligible. From the cross-sectional observation conducted to confirm the impregnation state of the matrix resin, no voids were observed in the molded products regardless of molding time or molding pressure, indicating that resin impregnation into the carbon fiber bundle of the open-fiber mixed yarn fabric was completed at a molding pressure of 5 MPa and a molding time of 5 min.

An investigation into self-sensing property of hat-shaped 3D orthogonal woven composite under bending test

2018 ◽  
Vol 38 (4) ◽  
pp. 149-166 ◽  
Author(s):  
Xiaoying Cheng ◽  
Hongshui Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Sensor Arrays ◽  
Woven Fabric ◽  
Bending Test ◽  
Fiber Array ◽  
Reinforced Composite ◽  
Resistance Variation ◽  
Deformation Distribution ◽  
3D Orthogonal Woven

In this paper, the influence of damage and deformation on the electrical property of carbon fibers in the hat-shaped 3D orthogonal woven fabric-reinforced composite structure is studied. A method of producing parallel sensor arrays was proposed, in which the warp yarns made of carbon fibers were separated by isolated Kevlar fibers as weft yarns and Z-yarns. The sensor array unitized the self-sensing property of carbon fiber and could detect the damage and deformation distribution along the transverse direction of the composite under bending tests. Both the experiments and simulations had been conducted to analyze the mechanical and electrical responses of the carbon fiber array. By comparing the experimental results and simulation data, the method was validated and the influences of damage and deformation distribution on the resistance variation of carbon fibers were revealed.

Cytocompatibility of Carbon Nanofiber Materials for Neural Applications

2003 ◽  
Vol 774 ◽  
Author(s):  
Janice L. McKenzie ◽  
Michael C. Waid ◽  
Riyi Shi ◽  
Thomas J. Webster
Keyword(s):  
Carbon Fiber ◽  
Surface Energy ◽  
Carbon Nanofibers ◽  
Carbon Fibers ◽  
Carbon Nanofiber ◽  
Fiber Composite ◽  
Scar Tissue ◽  
Pc 12 Cells ◽  
Low Surface Energy ◽  
Poly Carbonate

AbstractSince the cytocompatibility of carbon nanofibers with respect to neural applications remains largely uninvestigated, the objective of the present in vitro study was to determine cytocompatibility properties of formulations containing carbon nanofibers. Carbon fiber substrates were prepared from four different types of carbon fibers, two with nanoscale diameters (nanophase, or less than or equal to 100 nm) and two with conventional diameters (or greater than 200 nm). Within these two categories, both a high and a low surface energy fiber were investigated and tested. Astrocytes (glial scar tissue-forming cells) and pheochromocytoma cells (PC-12; neuronal-like cells) were seeded separately onto the substrates. Results provided the first evidence that astrocytes preferentially adhered on the carbon fiber that had the largest diameter and the lowest surface energy. PC-12 cells exhibited the most neurites on the carbon fiber with nanodimensions and low surface energy. These results may indicate that PC-12 cells prefer nanoscale carbon fibers while astrocytes prefer conventional scale fibers. A composite was formed from poly-carbonate urethane and the 60 nm carbon fiber. Composite substrates were thus formed using different weight percentages of this fiber in the polymer matrix. Increased astrocyte adherence and PC-12 neurite density corresponded to decreasing amounts of the carbon nanofibers in the poly-carbonate urethane matrices. Controlling carbon fiber diameter may be an approach for increasing implant contact with neurons and decreasing scar tissue formation.

Improvement of quality of carbon fiber rods by the impregnation of carbon fibers with oligoorganosiloxanes

2021 ◽  
Vol 70 (4) ◽  
pp. 767-772
Author(s):  
N. G. Mazhorova ◽  
P. V. Ivanov ◽  
O. V. Zaichenko ◽  
A. V. Lakhin ◽  
S. Yu. Kanterin ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers

scholarly journals Lightweight Cellulose/Carbon Fiber Composite Foam for Electromagnetic Interference (EMI) Shielding

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Carbon Fiber Composite ◽  
Foaming Process ◽  
Long Carbon Fibers

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

Graphene oxide modified carbon fiber reinforced epoxy composites

2020 ◽  
Vol 40 (5) ◽  
pp. 415-420 ◽  
Author(s):  
Yasin Altin ◽  
Hazal Yilmaz ◽  
Omer Faruk Unsal ◽  
Ayse Celik Bedeloglu
Keyword(s):  
Graphene Oxide ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Spray Coating ◽  
Sem Analysis ◽  
Epoxy Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Quick Method ◽  
Carbon Fiber Reinforced

AbstractThe interfacial interaction between the fiber and matrix is the most important factor which influences the performance of the carbon fiber-epoxy composites. In this study, the graphitic surface of the carbon fibers was modified with graphene oxide nanomaterials by using a spray coating technique which is an easy, cheap, and quick method. The carbon fiber-reinforced epoxy matrix composites were prepared by hand layup technique using neat carbon fibers and 0.5, 1 and 2% by weight graphene oxide (GO) modified carbon fibers. As a result of SEM analysis, it was observed that GO particles were homogeneously coated on the surface of the carbon fibers. Furthermore, Young's modulus increased from 35.14 to 43.40 GPa, tensile strength increased from 436 to 672 MPa, and the elongation at break was maintained around 2% even in only 2% GO addition.

scholarly journals Effect of Mechanical Pretreatments on Damage Mechanisms and Fracture Toughness in CFRP/Epoxy Joints

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1512
Author(s):  
Chiara Morano ◽  
Ran Tao ◽  
Marco Alfano ◽  
Gilles Lubineau
Keyword(s):  
Fracture Toughness ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Polymer Matrix ◽  
Mechanical Tests ◽  
Adhesive Joints ◽  
Fiber Reinforced Polymers ◽  
Composite Joints ◽  
Damage Mechanisms ◽  
Grit Blasting

Adhesive bonding of carbon-fiber-reinforced polymers (CFRPs) is a key enabling technology for the assembly of lightweight structures. Surface pretreatment is necessary to remove contaminants related to material manufacturing and ensure bond reliability. The present experimental study focuses on the effect of mechanical abrasion on the damage mechanisms and fracture toughness of CFRP/epoxy joints. The analyzed CFRP plates were provided with a thin layer of surface epoxy matrix and featured enhanced sensitivity to surface preparation. Various degrees of morphological modification and fairly controllable carbon fiber exposure were obtained using sanding with emery paper and grit-blasting with glass particles. In the sanding process, different grit sizes of SiC paper were used, while the grit blasting treatment was carried by varying the sample-to-gun distance and the number of passes. Detailed surveys of surface topography and wettability were carried out using various methods, including scanning electron microscopy (SEM), contact profilometry, and wettability measurements. Mechanical tests were performed using double cantilever beam (DCB) adhesive joints. Two surface conditions were selected for the experiments: sanded interfaces mostly made of a polymer matrix and grit-blasted interfaces featuring a significant degree of exposed carbon fibers. Despite the different topographies, the selected surfaces displayed similar wettability. Besides, the adhesive joints with sanded interfaces had a smooth fracture response (steady-state crack growth). In contrast, the exposed fibers at grit-blasted interfaces enabled large-scale bridging and a significant R-curve behavior. While it is often predicated that quality composite joints require surfaces with a high percentage of the polymer matrix, our mechanical tests show that the exposure of carbon fibers can facilitate a remarkable toughening effect. These results open up for additional interesting prospects for future works concerning toughening of composite joints in automotive and aerospace applications.

Surface and Composite Interface of Carbon Fiber Modified by Grafting of Diethanolamine

2009 ◽  
Vol 79-82 ◽  
pp. 497-500 ◽  
Author(s):  
Lei Chen ◽  
Zhi Wei Xu ◽  
Jia Lu Li ◽  
Xiao Qing Wu ◽  
Li Chen
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Irradiation Dose ◽  
Interlaminar Shear Strength ◽  
Epoxy Composites ◽  
Composite Interface ◽  
Γ Ray ◽  
Interlaminar Shear

The γ-ray co-irradiation method was employed to study the effect of diethanolamine modification on the surface of carbon fiber (CF) and the interfacial properties of CF/epoxy composites. Compared with the original carbon fiber, the surface of modified fibers became rougher. The amount of oxygen-containing functional groups was increased and the nitrogen element was detected after irradiation grafting. The interlaminar shear strength (ILSS) of composites reinforced by carbon fibers irradiated in diethanolamine solution was increased and then decreased as the irradiation dose increased. The ILSS of CF/epoxy composites was enhanced by 16.1% at 200kGy dose, compared with that of untreated one. The γ-ray irradiation grafting is expected to be a promising method for the industrialized modification of carbon fibers.

Preparation and Characterization of Activated Carbon Fibers from Jute Fibers by Phosphoric Acid Activation

2012 ◽  
Vol 184-185 ◽  
pp. 1110-1113 ◽  
Author(s):  
Li Fen He ◽  
Qi Xia Liu ◽  
Tao Ji ◽  
Qiang Gao
Keyword(s):  
Activated Carbon ◽  
Carbon Fiber ◽  
Phosphoric Acid ◽  
Carbon Fibers ◽  
Activated Carbon Fibers ◽  
Optimum Conditions ◽  
Activation Time ◽  
Activation Temperature ◽  
Jute Fibers ◽  
Activating Agent

Various jute-based activated carbon fibers were prepared by using jute fibers as raw materials and phosphoric acid as activating agent. The effects of three main factors such as concentration of activating agent, activation temperature and activation time on the yield and adsorptive properties of active carbon fibers were investigated via orthogonal experiments. The surface physical morphology of jute-based activated carbon fiber was also observed by using Scanning Electron Microscope. Results showed that the optimum conditions were phosphoric acid concentration of 4 mol/L, activation temperature of 600 °C and activation time of 1h. The yield, iodine number and amount of methylene blue adsorption of the active carbon fiber prepared under optimum conditions were 37.99 %, 1208.87 mg/g and 374.65 mg/g, respectively.

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