scholarly journals Mixed-conducting particulate composites for soft electronics

2020 ◽  
Vol 6 (17) ◽  
pp. eaaz6767 ◽  
Author(s):  
Patricia Jastrzebska-Perfect ◽  
George D. Spyropoulos ◽  
Claudia Cea ◽  
Zifang Zhao ◽  
Onni J. Rauhala ◽  
...  
Keyword(s):  
High Performance ◽  
Particulate Composite ◽  
Particulate Composites ◽  
Spatiotemporal Resolution ◽  
Electrophysiological Signals ◽  
Neurophysiological Data ◽  
Material Solution ◽  
Soft Electronics ◽  
Single Material ◽  
Local Advanced

Bioelectronic devices should optimally merge a soft, biocompatible tissue interface with capacity for local, advanced signal processing. Here, we introduce an organic mixed-conducting particulate composite material (MCP) that can form functional electronic components by varying particle size and density. We created MCP-based high-performance anisotropic films, independently addressable transistors, resistors, and diodes that are pattern free, scalable, and biocompatible. MCP enabled facile and effective electronic bonding between soft and rigid electronics, permitting recording of neurophysiological data at the resolution of individual neurons from freely moving rodents and from the surface of the human brain through a small opening in the skull. We also noninvasively acquired high–spatiotemporal resolution electrophysiological signals by directly interfacing MCP with human skin. MCP provides a single-material solution to facilitate development of bioelectronic devices that can safely acquire, transmit, and process complex biological signals.

Micro-Crack Propagation in Particulate Composite with Different Types of Matrix

2012 ◽  
Vol 245 ◽  
pp. 138-143 ◽  
Author(s):  
Zdeněk Majer ◽  
Luboš Náhlík
Keyword(s):  
Polymer Matrix ◽  
High Performance ◽  
Construction Materials ◽  
Particulate Composite ◽  
Polymer Particle ◽  
Material Behavior ◽  
Particulate Composites ◽  
Mineral Filler ◽  
Non Linear ◽  
The Matrix

Particulate composites with polymer matrix and solid fillers are one of important types of materials. Generally, these materials are usually used as construction materials, high-performance engineering materials or protective organic coatings. The main aim of a present paper is an estimation of the micro-crack behavior in the particulate composite with non-linear polymer matrix. The polymer matrix filled by magnesia-based mineral filler is investigated by means of the finite element method. A non-linear material behavior of the matrix was obtained from experiment as well as properties of mineral filler. Numerical model on the base of representative plane element (RPE) was developed. The results show that the presence of interphase between particle and matrix can improve fracture toughness of polymer particle composite through debonding process. The conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in particulate composites with respect to interphase.

Effective Stiffness of a Debonded Particle in Particulate Composites

2007 ◽  
Vol 334-335 ◽  
pp. 33-36 ◽  
Author(s):  
Akihiro Wada ◽  
Yusuke Nagata ◽  
Shi Nya Motogi
Keyword(s):  
Three Dimensional ◽  
Particulate Composite ◽  
Spherical Particles ◽  
Particulate Composites ◽  
Particle Volume ◽  
Equivalent Inclusion Method ◽  
Equivalent Inclusion ◽  
Load Carrying ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this study, partially debonded spherical particles in a particulate composite are analyzed by three-dimensional finite element method to investigate their load carrying capacities, and the way to replace a debonded particle with an equivalent inclusion is examined. The variation in Young’s modulus and Poisson’s ratio of a composite with the debonded angle was evaluated for different particle arrangements and particle volume fractions, which in turn compared with the results derived from the equivalent inclusion method. Consequently, it was found that by replacing a debonded particle with an equivalent orthotropic one, the macroscopic behavior of the damaged composite could be reproduced so long as the interaction between neighboring particles is negligible.

Numerical Modeling of Macroscopic Behavior of Particulate Composite with Crosslinked Polymer Matrix

2011 ◽  
Vol 465 ◽  
pp. 129-132
Author(s):  
Luboš Náhlík ◽  
Bohuslav Máša ◽  
Pavel Hutař
Keyword(s):  
Young’S Modulus ◽  
Polymer Matrix ◽  
Young's Modulus ◽  
Numerical Models ◽  
Strain Curve ◽  
Particulate Composite ◽  
Material Behavior ◽  
Particulate Composites ◽  
Stress Strain ◽  
Crosslinked Polymer

Particulate composites with crosslinked polymer matrix and solid fillers are one of important classes of materials such as construction materials, high-performance engineering materials, sealants, protective organic coatings, dental materials, or solid explosives. The main focus of a present paper is an estimation of the macroscopic Young’s modulus and stress-strain behavior of a particulate composite with polymer matrix. The particulate composite with a crosslinked polymer matrix in a rubbery state filled by an alumina-based mineral filler is investigated by means of the finite element method. A hyperelastic material behavior of the matrix was modeled by the Mooney-Rivlin material model. Numerical models on the base of unit cell were developed. The numerical results obtained were compared with experimental stress-strain curve and value of initial Young’s modulus. The paper can contribute to a better understanding of the behavior and failure of particulate composites with a crosslinked polymer matrix.

Dynamic Attenuation and Compressive Characterization of Syntactic Foams

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Bhaskar Ale ◽  
Carl-Ernst Rousseau
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
Ultrasonic Attenuation ◽  
Dynamic Properties ◽  
High Strength ◽  
Particulate Composites ◽  
Syntactic Foams ◽  
Core Elements ◽  
Marine Applications ◽  
Damping Materials

Hollow particulate composites are lightweight, have high compressive strength, are low moisture absorbent, have high damping materials, and are used extensively in aerospace, marine applications, and in the manufacture of sandwich composites core elements. The high performance of these materials is achieved by adding high strength hollow glass particulates (microballoons) to an epoxy matrix, forming epoxy-syntactic foams. The present study focuses on the effect of volume fraction and microballoon size on the ultrasonic and dynamic properties of Epoxy Syntactic Foams. Ultrasonic attenuation coefficient from an experiment is compared with a previously developed theoretical model for low volume fractions that takes into account attenuation loss due to scattering and absorption. The guidelines of ASTM Standard E 664-93 are used to compute the apparent attenuation. Quasi-static compressive tests were also conducted to fully characterize the material. Both quasi-static and dynamic properties, as well as coefficients of attenuation and ultrasonic velocities are found to be strongly dependent upon the volume fraction and size of the microballoons.

scholarly journals High-Performance Computing Framework Based on Distributed Systems for Large-Scale Neurophysiological Data

2021 ◽  
Author(s):  
Mohsen Hadianpour ◽  
Ehsan Rezayat ◽  
Mohammad-Reza Dehaqani
Keyword(s):  
High Performance Computing ◽  
High Performance ◽  
Large Scale ◽  
Electrophysiological Recording ◽  
Neural Data ◽  
Data Framework ◽  
Neurophysiological Data ◽  
Computing Framework ◽  
Performance Computing ◽  
Neuroscience Community

Abstract Due to the significantly drastic progress and improvement in neurophysiological recording technologies, neuroscientists have faced various complexities dealing with unstructured large-scale neural data. In the neuroscience community, these complexities could create serious bottlenecks in storing, sharing, and processing neural datasets. In this article, we developed a distributed high-performance computing (HPC) framework called `Big neuronal data framework' (BNDF), to overcome these complexities. BNDF is based on open-source big data frameworks, Hadoop and Spark providing a flexible and scalable structure. We examined BNDF on three different large-scale electrophysiological recording datasets from nonhuman primate’s brains. Our results exhibited faster runtimes with scalability due to the distributed nature of BNDF. We compared BNDF results to a widely used platform like MATLAB in an equitable computational resource. Compared with other similar methods, using BNDF provides more than five times faster performance in spike sorting as a usual neuroscience application.

scholarly journals Electro-plasmonic nanoantenna: A nonfluorescent optical probe for ultrasensitive label-free detection of electrophysiological signals

2019 ◽  
Vol 5 (10) ◽  
pp. eaav9786 ◽  
Author(s):  
Ahsan Habib ◽  
Xiangchao Zhu ◽  
Uryan I. Can ◽  
Maverick L. McLanahan ◽  
Pinar Zorlutuna ◽  
...  
Keyword(s):  
Electric Field ◽  
Field Measurements ◽  
Optical Probe ◽  
Optical Recording ◽  
High Temporal Resolution ◽  
Label Free ◽  
Spatiotemporal Resolution ◽  
Photon Count ◽  
Label Free Detection ◽  
Electrophysiological Signals

Harnessing the unprecedented spatiotemporal resolution capability of light to detect electrophysiological signals has been the goal of scientists for nearly 50 years. Yet, progress toward that goal remains elusive due to lack of electro-optic translators that can efficiently convert electrical activity to high photon count optical signals. Here, we introduce an ultrasensitive and extremely bright nanoscale electric-field probe overcoming the low photon count limitations of existing optical field reporters. Our electro-plasmonic nanoantennas with drastically enhanced cross sections (~104 nm2 compared to typical values of ~10−2 nm2 for voltage-sensitive fluorescence dyes and ~1 nm2 for quantum dots) offer reliable detection of local electric-field dynamics with remarkably high sensitivities and signal–to–shot noise ratios (~60 to 220) from diffraction-limited spots. In our electro-optics experiments, we demonstrate high-temporal resolution electric-field measurements at kilohertz frequencies and achieved label-free optical recording of network-level electrogenic activity of cardiomyocyte cells with low-intensity light (11 mW/mm2).

Computational Evaluation of Effective Conductivity of Particulate Composites with Imperfect Interfaces

2009 ◽  
Vol 631-632 ◽  
pp. 35-40
Author(s):  
M. Zhang ◽  
Peng Cheng Zhai ◽  
Qing Jie Zhang
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Effective Properties ◽  
Effective Conductivity ◽  
Three Dimensional ◽  
Particulate Composite ◽  
Imperfect Interface ◽  
Particulate Composites ◽  
Imperfect Interfaces ◽  
Volume Fractions

This paper is aimed to numerically evaluate the effective thermal conductivity of randomly distributed spherical particle composite with imperfect interface between the constituents. A numerical homogenization technique based on the finite element method (FEM) with representative volume element (RVE) was used to evaluate the effective properties with periodic boundary conditions. Modified random sequential adsorption algorithm (RSA) is applied to generate the three dimensional RVE models of randomly distributed spheres of identical size with the volume fractions up to 50%. Several investigations have been conducted to estimate the influence of the imperfect interfaces on the effective conductivity of particulate composite. Numerical results reveal that for the given composite, due to the existence of an interfacial thermal barrier resistance, the effective thermal conductivity depends not only on the volume fractions of the particle but on the particle size.

scholarly journals Single Molecular Catalysis Identifying Activation Energy of Intermediate Product and Rate-Limiting Step in Plasmonic Photocatalysis

2019 ◽  
Author(s):  
Di Li
Keyword(s):  
Activation Energy ◽  
High Performance ◽  
Variable Temperature ◽  
Chemical Conversion ◽  
Catalytic Performance ◽  
Localized Surface Plasmon ◽  
Spatiotemporal Resolution ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Plasmon mediated photocatalysis provides a novel strategy for harvesting solar energy. Identification of rate determining step and its activation energy in plasmon mediated photocatalysis plays critical roles for understanding the contribution of hot carriers that facilitates rational designing catalysts with integrated high photo-chemical conversion efficiency and catalytic performance. However, it remains a challenge due to a lack of research tools with spatiotemporal resolution that capable of capturing intermediates. In this work, we used a single molecular fluorescence approach to investigate a localized surface plasmon resonance (LSPR) enhanced photocatalytic reaction with sub-turnover resolution. By introducing variable temperature as an independent parameter in plasmonic photocatalysis, the activation energies of tandem reaction steps, including intermediate generation, product generation and product dissociation, were clearly differentiated, and intermediates generation was found to be the rate-limiting step. Remarkably, the cause of plasmon enhanced catalysis performance was found to be its ability of lowering the activation energy of intermediates generation. This study gives new insight into the photo-chemical energy conversion pathways in plasmon enhanced photocatalysis and sheds light on designing high performance plasmonic catalysts.

scholarly journals Single Molecular Catalysis Identifying Activation Energy of Intermediate Product and Rate-Limiting Step in Plasmonic Photocatalysis

2019 ◽  
Author(s):  
Di Li
Keyword(s):  
Activation Energy ◽  
High Performance ◽  
Variable Temperature ◽  
Chemical Conversion ◽  
Catalytic Performance ◽  
Localized Surface Plasmon ◽  
Spatiotemporal Resolution ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Plasmon mediated photocatalysis provides a novel strategy for harvesting solar energy. Identification of rate determining step and its activation energy in plasmon mediated photocatalysis plays critical roles for understanding the contribution of hot carriers that facilitates rational designing catalysts with integrated high photo-chemical conversion efficiency and catalytic performance. However, it remains a challenge due to a lack of research tools with spatiotemporal resolution that capable of capturing intermediates. In this work, we used a single molecular fluorescence approach to investigate a localized surface plasmon resonance (LSPR) enhanced photocatalytic reaction with sub-turnover resolution. By introducing variable temperature as an independent parameter in plasmonic photocatalysis, the activation energies of tandem reaction steps, including intermediate generation, product generation and product dissociation, were clearly differentiated, and intermediates generation was found to be the rate-limiting step. Remarkably, the cause of plasmon enhanced catalysis performance was found to be its ability of lowering the activation energy of intermediates generation. This study gives new insight into the photo-chemical energy conversion pathways in plasmon enhanced photocatalysis and sheds light on designing high performance plasmonic catalysts.

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