scholarly journals A Low Contact Impedance Medical Flexible Electrode Based on a Pyramid Array Micro-Structure

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 57 ◽  
Author(s):  
Song Wang ◽  
Jin Yan ◽  
Canlin Zhu ◽  
Jialin Yao ◽  
Qiusheng Liu ◽  
...  
Keyword(s):  
Contact Area ◽  
Unit Area ◽  
Medical Systems ◽  
Transitional Layer ◽  
Flexible Electrode ◽  
Contact Impedance ◽  
Flexible Electrodes ◽  
Quality Signals ◽  
Scanning Frequency ◽  
Good Biocompatibility

Flexible electrodes are extensively used to detect signals in electrocardiography, electroencephalography, electro-ophthalmography, and electromyography, among others. These electrodes can also be used in wearable and implantable medical systems. The collected signals directly affect doctors’ diagnoses of patient etiology and are closely associated with patients’ life safety. Electrodes with low contact impedance can acquire good quality signals. Herein, we established a method of arraying pyramidal microstructures on polydimethylsiloxane (PDMS) substrates to increase the contact area of electrodes, and a parylene transitional layer is coated between PDMS substrates and metal membranes to enhance the bonding force, finally reducing the impedance of flexible electrodes. Experimental results demonstrated that the proposed methods were effective. The contact area of the fabricated electrode increased by 18.15% per unit area, and the contact impedance at 20 Hz to 1 kHz scanning frequency ranged from 23 to 8 kΩ, which was always smaller than that of a commercial electrode. Overall, these results indicated the excellent performance of the fabricated electrode given its low contact impedance and good biocompatibility. This study can also serve as a reference for further electrode research and application in wearable and implantable medical systems.

Assembly of porous NiO nanowires on carbon cloth as a flexible electrode for high-performance supercapacitors

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 74874-74877 ◽  
Author(s):  
Yi-Hang Peng ◽  
Mei-Xia Guo ◽  
Fu Shao ◽  
Si Liu ◽  
Quan Zhu ◽  
...  
Keyword(s):  
High Performance ◽  
Carbon Cloth ◽  
Flexible Electrode ◽  
Flexible Electrodes

Porous NiO nanowire layers were deposited on conductive carbon cloth and are used as flexible electrodes for high performance supercapacitors.

scholarly journals The effect of flexible joint-like elements on the adhesive performance of nature-inspired bent mushroom-like fibers

2018 ◽  
Vol 9 ◽  
pp. 2893-2905 ◽  
Author(s):  
Elliot Geikowsky ◽  
Serdar Gorumlu ◽  
Burak Aksak
Keyword(s):  
Elastic Modulus ◽  
Contact Area ◽  
Unit Area ◽  
Soft Material ◽  
Soft Or ◽  
Fiber Density ◽  
Adhesion Properties ◽  
Flexible Joint ◽  
Ladybird Beetles ◽  
Stiff Joint

Many organisms rely on densely packed, tilted and curved fibers of various dimensions to attach to surfaces. While the high elastic modulus of these fibers enables an extremely large number of fibers per unit area, where each fiber stands freely without sticking to its neighbors, the tilt/curvature provides them with the compliance and the directional adhesion properties to attach strongly and efficiently to a surface. Recent studies have revealed that many of such organisms also feature materials with a graded elastic modulus that is tailored towards improving the contact area without sacrificing the fiber density. In particular, for male ladybird beetles, research has shown that the adhesive setae feature a material gradient such that the elastic modulus of the material at the junction between the stalk and the divergent distal end is close to minimum. This soft material acts like a flexible joint, improving the bending compliance of the tip. Here, we mimic this feature using tilted, mushroom-like, stiff fibers comprised of a stiff stalk of elastic modulus 126 MPa, a softer tip of elastic modulus 8.89 MPa, and a joint-like element of elastic modulus 0.45 MPa (very soft), 8.89 MPa (soft), or 126 MPa (stiff) in between. The results from load–drag–pull (LDP) experiments performed along (gripping) and against (releasing) the tilt direction indicate that the soft and the very soft joint fibers performed superior to the stiff joint fibers and maintained directionally dependent performance. The soft joint fibers achieved up to 22 kPa in shear and 110 kPa in pull-off stress in the gripping direction, which are twice and ten times higher than that in the releasing direction, respectively. A model to optimize the elastic modulus of the joint-like elements to enable sliding without peeling of the tips has been proposed.

An “inverted load” strategy to fabricate interface-optimized flexible electrodes with superior electrochemical performance and ultrastability

2020 ◽  
Vol 8 (32) ◽  
pp. 11128-11137
Author(s):  
Ying Sun ◽  
Ying Yang ◽  
Ning-Bo Li ◽  
Meng Wang ◽  
Xu-Man Chen ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Flexible Electrode ◽  
Flexible Electrodes

An “inverted load” strategy for interface optimization has been proposed to fabricate flexible electrode with superior electrochemical performance and ultrastability.

scholarly journals Fabrication of Flexible Electrode with Sub-Tenth Micron Thickness Using Heat-Induced Peelable Pressure-Sensitive Adhesive Containing Amide Groups

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1250
Author(s):  
Hyebeom Shin ◽  
Eunseong Yang ◽  
Yong-Hoon Kim ◽  
Min-Gi Kwak ◽  
Youngmin Kim
Keyword(s):  
Pressure Sensitive Adhesive ◽  
Flexible Electrode ◽  
Flexible Electrodes ◽  
Flexible Devices ◽  
Pressure Sensitive ◽  
Mechanical Durability ◽  
Thick Substrate ◽  
Order Of Magnitude ◽  
Increasing Demand ◽  
Pet Film

In response to the increasing demand for flexible devices, there is increasing effort to manufacture flexible electrodes. However, the difficulty of handling a thin film is an obstacle to the production of flexible electrodes. In this study, a heat-induced peelable pressure-sensitive adhesive (h-PSA) was fabricated and used to manufacture a flexible electrode with sub-tenth micron thickness. Unlike the control PSA, the incorporation of amide groups made the h-PSA fail through adhesive failure at temperatures ranging from 20 to 80 °C. Compared to the peeling adhesion (1719 gf/in) of h-PSA measured at 20 °C, the value (171 gf/in) measured at 80 °C was decreased by one order of magnitude. Next, the 8 μm thick polyethylene terephthalate (PET) film was attached on a thick substrate (50 μm) via h-PSA, and Mo/Al/Mol patterns were fabricated on the PET film through sputtering, photolithography, and wet-etching processes. The thick substrate alleviated the difficulty of handling the thin PET film during the electrode fabrication process. Thanks to the low peel force and clean separation of the h-PSA at 80 °C, the flexible electrode of metal patterns on the PET (8 μm) film was isolated from the substrate with little change (<1%) in electrical conductivity. Finally, the mechanical durability of the flexible electrode was evaluated by a U-shape folding test, and no cracking or delamination was observed after 10,000 test cycles.

Vertically aligned carbon nanotube@MnO2nanosheet arrays grown on carbon cloth for high performance flexible electrodes of supercapacitors

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 77437-77442 ◽  
Author(s):  
Xiao-Jun Li ◽  
Yong Zhao ◽  
Wei-Guo Chu ◽  
Yue Wang ◽  
Zhen-Jun Li ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
High Performance ◽  
Carbon Cloth ◽  
Flexible Electrode ◽  
Flexible Electrodes ◽  
Vertically Aligned

The VACNTs@MnO2arrays grown on carbon cloth can act as the high performance flexible electrode for supercapacitors.

Role of double interfaces in inspiring energy storage devices in CC@Ni(OH)Cl@NiO flexible electrodes

2020 ◽  
Vol 4 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Sixian Fu ◽  
Liping Li ◽  
Lingshen Meng ◽  
Mengyue Gao ◽  
Shuaikai Xu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Electrochemical Performance ◽  
Energy Storage Devices ◽  
Flexible Electrode ◽  
Flexible Electrodes ◽  
Storage Devices ◽  
Electronic Behavior

The synergistic double interfaces in CC@Ni(OH)Cl@NiO flexible electrode stabilize Ni–O covalency and stimulate active electronic behavior for superior electrochemical performance.

Contact analysis of an anisotropic half-domain with micropatterns considering friction

2014 ◽  
Vol 03 (01) ◽  
pp. 1450005
Author(s):  
Hideo Koguchi ◽  
Shuma Suzuki ◽  
Masahiro Taroura
Keyword(s):  
Fourier Transform ◽  
Contact Area ◽  
Principal Axis ◽  
Unit Area ◽  
Material Anisotropy ◽  
Friction Property ◽  
Stick Slip ◽  
Slip Region ◽  
Tangential Forces ◽  
Anisotropic Elastic

In the present study, a contact problem between a spherical indenter and a half-anisotropic elastic region with a micropattern is solved under normal and tangential forces considering friction. The surface Green's function, and the discrete convolution and fast Fourier transform (DC–FFT) method are used to calculate the displacements on a contact area, and the conjugate gradient (CG) method is used to calculate the contact pressure, the contact area, shear tractions, and the stick-slip region. The influences of the shape and density (the pattern area per unit area) of the micropattern and the material anisotropy in the substrate on the friction property of the substrate are investigated. In the present study, substrates with circular and square micropatterns are used in the analysis. The results of the analysis revealed that the shear tractions are concentrated at the edges and corners of the circular and square patterns, respectively. The apparent friction coefficient varies with the direction of the anisotropic principal axis.

Normal Contact Stiffness on Unit Area of a Mechanical Joint Surface Considering Perfectly Elastic Elliptical Asperities

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
J. P. Shi ◽  
K. Ma ◽  
Z. Q. Liu
Keyword(s):  
Contact Area ◽  
Unit Area ◽  
Rough Surfaces ◽  
Contact Stiffness ◽  
Unit Length ◽  
Joint Surface ◽  
Normal Contact ◽  
Mechanical Joint ◽  
Normal Contact Stiffness ◽  
The Relationship

Based on the Greenwood and Williamson theory, an assumption about the contact-area size of asperities on rough surfaces is proposed under the premise that the height of these asperities on rough surfaces is a Gaussian distribution. A formula has been derived to measure the number of asperities on 2D surfaces. The contact stiffness on a unit length of a 1D outline and that on a unit area of 2D surfaces are presented based on a formula for determining the number of asperities. The relationship between macro parameters, such as contact stiffness and micro parameters on the joint surface, is established.

Fabrication of flexible electrode with trace Rh based on Polypyrrole for hydrogen evolution reaction

2021 ◽  
Author(s):  
Tiantian Li ◽  
Xin Zhang ◽  
You Li ◽  
Wenchao Li ◽  
Shijie Jia ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Catalytic Performance ◽  
Flexible Electrode ◽  
Flexible Electrodes

Multi-potential steps was proposed for constructing flexible electrodes PPy/Rh film. The obtained PPy/Rh films exhibit excellent HER catalytic performance and it can be used as a flexible electrode, which maintains...

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

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