scholarly journals Graphene-Based Electrode Materials for Neural Activity Detection

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6170
Author(s):  
Weichen Wei ◽  
Xuejiao Wang
Keyword(s):  
Neural Activity ◽  
High Performance ◽  
Electrode Materials ◽  
Neurological Diseases ◽  
Activity Detection ◽  
Neural Signals ◽  
Neural Electrode ◽  
Neural Electrodes ◽  
Wide Range

The neural electrode technique is a powerful tool for monitoring and regulating neural activity, which has a wide range of applications in basic neuroscience and the treatment of neurological diseases. Constructing a high-performance electrode–nerve interface is required for the long-term stable detection of neural signals by electrodes. However, conventional neural electrodes are mainly fabricated from rigid materials that do not match the mechanical properties of soft neural tissues, thus limiting the high-quality recording of neuroelectric signals. Meanwhile, graphene-based nanomaterials can form stable electrode–nerve interfaces due to their high conductivity, excellent flexibility, and biocompatibility. In this literature review, we describe various graphene-based electrodes and their potential application in neural activity detection. We also discuss the biological safety of graphene neural electrodes, related challenges, and their prospects.

Interpenetrating Gels as Conducting/Adhering Matrices Enabling High-Performance Silicon Anodes

2021 ◽  
Author(s):  
Tingting Xia ◽  
Chengfei Xu ◽  
Pengfei Dai ◽  
Xiaoyun Li ◽  
Riming Lin ◽  
...  
Keyword(s):  
Energy Storage ◽  
High Performance ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Electrochemical Energy Storage ◽  
Active Materials ◽  
Silicon Anodes ◽  
Weak Binding ◽  
Binding Forces

Three-dimensional (3D) conductive polymers are promising conductive matrices for electrode materials toward electrochemical energy storage. However, their fragile nature and weak binding forces with active materials could not guarantee long-term...

The preparations of nanoporous carbon with multi-heteroatoms co-doping from black liquor powders for supercapacitors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pengfei Hao ◽  
Yanjie Yi ◽  
Youming Li ◽  
Yi Hou
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Black Liquor ◽  
Nanoporous Carbon ◽  
Electrode System ◽  
Industrial Wastes ◽  
Co Doping ◽  
Paper Making ◽  
Symmetric Supercapacitor

Abstract A green and economically viable route without any additional activation agents and templates has been developed to synthesize biomass-derived nanoporous carbon for superior electric double-layer capacitors via direct pyrolysis of dried black liquor powders, which is the main waste in pulping and paper-making industry. The resulting carbon materials present hierarchical porosity and moderate specific surface area of 1134  m 2 g − 1 {\text{m}^{2}}\hspace{0.1667em}{\text{g}^{-1}} , as well as multi-heteroatoms co-doping such as N, S, Na and K, which exist originally in black liquor. When evaluated as electrode materials for supercapacitors in 6 M KOH aqueous electrolyte, the-prepared carbon samples deliver a significantly high gravimetric capacitance of 331  F g − 1 \text{F}\hspace{0.1667em}{\text{g}^{-1}} at 0.5  A g − 1 \text{A}\hspace{0.1667em}{\text{g}^{-1}} in a three-electrode system. Moreover, the fabricated symmetric supercapacitor also possesses a gravimetric capacitance of 211  F g − 1 \text{F}\hspace{0.1667em}{\text{g}^{-1}} at 0.5  A g − 1 \text{A}\hspace{0.1667em}{\text{g}^{-1}} , with an impressive long-term cycling stability of 92 % capacitance retention after 3000 cycles. This work explores a suitable and scalable approach for mass production of high-performance electrode materials with industrial wastes on the base of cost-efficiency and environment-friendship.

scholarly journals Optimizing the neuron-electrode interface for chronic bioelectronic interfacing

2020 ◽  
Vol 49 (1) ◽  
pp. E7
Author(s):  
Conor Keogh
Keyword(s):  
Electrode Materials ◽  
Neurological Diseases ◽  
Tissue Reaction ◽  
Biological Interactions ◽  
Implanted Electrodes ◽  
Tissue Integration ◽  
Closed Loop Systems ◽  
Electrode Interface ◽  
Neural Interfacing

Engineering approaches have vast potential to improve the treatment of disease. Brain-machine interfaces have become a well-established means of treating some otherwise medically refractory neurological diseases, and they have shown promise in many more areas. More widespread use of implanted stimulating and recording electrodes for long-term intervention is, however, limited by the difficulty in maintaining a stable interface between implanted electrodes and the local tissue for reliable recording and stimulation.This loss of performance at the neuron-electrode interface is due to a combination of inflammation and glial scar formation in response to the implanted material, as well as electrical factors contributing to a reduction in function over time. An increasing understanding of the factors at play at the neural interface has led to greater focus on the optimization of this neuron-electrode interface in order to maintain long-term implant viability.A wide variety of approaches to improving device interfacing have emerged, targeting the mechanical, electrical, and biological interactions between implanted electrodes and the neural tissue. These approaches are aimed at reducing the initial trauma and long-term tissue reaction through device coatings, optimization of mechanical characteristics for maximal biocompatibility, and implantation techniques. Improved electrode features, optimized stimulation parameters, and novel electrode materials further aim to stabilize the electrical interface, while the integration of biological interventions to reduce inflammation and improve tissue integration has also shown promise.Optimization of the neuron-electrode interface allows the use of long-term, high-resolution stimulation and recording, opening the door to responsive closed-loop systems with highly selective modulation. These new approaches and technologies offer a broad range of options for neural interfacing, representing the possibility of developing specific implant technologies tailor-made to a given task, allowing truly personalized, optimized implant technology for chronic neural interfacing.

scholarly journals Plasma Metabolic Signature and Abnormalities in HIV-Infected Individuals on Long-Term Successful Antiretroviral Therapy

Metabolites ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 210 ◽  
Author(s):  
Hemalatha Babu ◽  
Maike Sperk ◽  
Anoop T. Ambikan ◽  
Gladys Rachel ◽  
Vinod Kumar Viswanathan ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Antiretroviral Therapy ◽  
High Performance ◽  
Neurological Diseases ◽  
Aromatic Amino Acids ◽  
Essential Amino Acids ◽  
Metabolic Abnormalities ◽  
Plasma Proteomics

Targeted metabolomics studies reported metabolic abnormalities in both treated and untreated people living with human immunodeficiency virus (HIV) (PLHIV). The present study aimed to understand the plasma metabolomic changes and predicted the risk of accelerated aging in PLHIV on long-term suppressive antiretroviral therapy (ART) in a case-control study setting and its association with the plasma proteomics biomarkers of inflammation and neurological defects. Plasma samples were obtained from PLHIV on successful long-term ART for more than five years (n = 22) and matched HIV-negative healthy individuals (n = 22, HC herein). Untargeted metabolite profiling was carried out using ultra-high-performance liquid chromatography/mass spectrometry/mass spectrometry (UHPLC/MS/MS). Plasma proteomics profiling was performed using proximity extension assay targeting 184 plasma proteins. A total of 250 metabolites differed significantly (p < 0.05, q < 0.1) between PLHIV and HC. Plasma levels of several essential amino acids except for histidine, branched-chain amino acids, and aromatic amino acids (phenylalanine, tyrosine, tryptophan) were significantly lower in PLHIV compared to HC. Machine-learning prediction of metabolite changes indicated a higher risk of inflammatory and neurological diseases in PLHIV. Metabolic abnormalities were observed in amino-acid levels, energetics, and phospholipids and complex lipids, which may reflect known differences in lipoprotein levels in PLHIV that can resemble metabolic syndrome (MetS).

Noncoding RNAs and RNA Editing in Brain Development, Functional Diversification, and Neurological Disease

2007 ◽  
Vol 87 (3) ◽  
pp. 799-823 ◽  
Author(s):  
Mark F. Mehler ◽  
John S. Mattick
Keyword(s):  
Nervous System ◽  
Rna Editing ◽  
Neurological Diseases ◽  
Cell Types ◽  
State Transitions ◽  
Long Term Memory ◽  
Protein Coding ◽  
Continuous State ◽  
Wide Range

The progressive maturation and functional plasticity of the nervous system in health and disease involve a dynamic interplay between the transcriptome and the environment. There is a growing awareness that the previously unexplored molecular and functional interface mediating these complex gene-environmental interactions, particularly in brain, may encompass a sophisticated RNA regulatory network involving the twin processes of RNA editing and multifaceted actions of numerous subclasses of non-protein-coding RNAs. The mature nervous system encompasses a wide range of cell types and interconnections. Long-term changes in the strength of synaptic connections are thought to underlie memory retrieval, formation, stabilization, and effector functions. The evolving nervous system involves numerous developmental transitions, such as neurulation, neural tube patterning, neural stem cell expansion and maintenance, lineage elaboration, differentiation, axonal path finding, and synaptogenesis. Although the molecular bases for these processes are largely unknown, RNA-based epigenetic mechanisms appear to be essential for orchestrating these precise and versatile biological phenomena and in defining the etiology of a spectrum of neurological diseases. The concerted modulation of RNA editing and the selective expression of non-protein-coding RNAs during seminal as well as continuous state transitions may comprise the plastic molecular code needed to couple the intrinsic malleability of neural network connections to evolving environmental influences to establish diverse forms of short- and long-term memory, context-specific behavioral responses, and sophisticated cognitive capacities.

Nanoporous Metals for Catalytic and Optical Applications

MRS Bulletin ◽  
2009 ◽  
Vol 34 (8) ◽  
pp. 569-576 ◽  
Author(s):  
Yi Ding ◽  
Mingwei Chen
Keyword(s):  
Optical Properties ◽  
Fuel Cell ◽  
High Performance ◽  
Electrode Materials ◽  
Three Dimensional ◽  
Functional Materials ◽  
Porous Network ◽  
Highly Active ◽  
Wide Range ◽  
Nanoporous Metals

AbstractNanoporous metals (NPMs) made by dealloying represent a class of functional materials with the unique structural properties of mechanical rigidity, electrical conductivity, and high corrosion resistance. They also possess a porous network structure with feature dimensions tunable within a wide range from a few nanometers to several microns. Coupled with a rich surface chemistry for further functionalization, NPMs have great potential for applications in heterogeneous catalysis, electrocatalysis, fuel cell technologies, biomolecular sensing, surface-enhanced Raman scattering (SERS), and plasmonics. This article summarizes recent advances in some of these areas and, in particular, we focus on the discussion of microstructure, catalytic, and optical properties of nanoporous gold (NPG). With advanced electron microscopy, three-dimensional tomographic reconstructions of NPG have been realized that yield quantitative characterizations of key morphological parameters involved in the intricate structure. Catalytic and electrocatalytic investigations demonstrate that bare NPG is already catalytically active for many important reactions such as CO and glucose oxidation. Surface functionalization with other metals, such as Pt, produces very efficient electrocatalysts, which have been used as promising fuel cell electrode materials with very low precious metal loading. Additionally, NPG and related materials possess outstanding optical properties in plasmonics and SERS. They hold promise to act as highly active, stable, and economically affordable substrates in high-performance instrumentation applications for chemical inspection and biomolecular diagnostics. Finally, we conclude with some perspectives that appear to warrant future investigation.

scholarly journals Light-weight Electrophysiology Hardware and Software Platform for Cloud-Based Neural Recording Experiments

2021 ◽  
Author(s):  
Kateryna Voituik ◽  
Jinghui Geng ◽  
Matthew G. Keefe ◽  
David F. Parks ◽  
Sebastian E. Sanso ◽  
...  
Keyword(s):  
Neural Activity ◽  
User Interaction ◽  
Neural Recording ◽  
Circuit Board ◽  
Raspberry Pi ◽  
Development Organization ◽  
Human Neurons ◽  
Wide Range ◽  
Processing Device

Objective. Neural activity represents a functional readout of neurons that is increasingly important to monitor in a wide range of experiments. Extracellular recordings have emerged as a powerful technique for measuring neural activity because these methods do not lead to the destruction or degradation of the cells being measured. Current approaches to electrophysiology have a low throughput of experiments due to manual supervision and expensive equipment. This bottleneck limits broader inferences that can be achieved with numerous long-term recorded samples. Approach. We developed Piphys, an inexpensive open source neurophysiological recording platform that consists of both hardware and software. It is easily accessed and controlled via a standard web interface through Internet of Things (IoT) protocols. Main Results. We used a Raspberry Pi as the primary processing device and Intan bioamplifier. We designed a hardware expansion circuit board and software to enable voltage sampling and user interaction. This standalone system was validated with primary human neurons, showing reliability in collecting real-time neural activity. Significance. The hardware modules and cloud software allow for remote control of neural recording experiments as well as horizontal scalability, enabling long-term observations of development, organization, and neural activity at scale.

scholarly journals “Validating silicon polytrodes with paired juxtacellular recordings: method and dataset”

2016 ◽  
Author(s):  
Joana P. Neto ◽  
Gonçalo Lopes ◽  
João Frazão ◽  
Joana Nogueira ◽  
Pedro Lacerda ◽  
...  
Keyword(s):  
Neural Activity ◽  
Single Neuron ◽  
Cross Validation ◽  
Electrode Materials ◽  
Validation Dataset ◽  
Neural Signals ◽  
Neural Structure ◽  
New Methods ◽  
New Algorithms

AbstractCross-validating new methods for recording neural activity is necessary to accurately interpret and compare the signals they measure. Here we describe a procedure for precisely aligning two probes for in vivo “paired-recordings” such that the spiking activity of a single neuron is monitored with both a dense extracellular silicon polytrode and a juxtacellular micro-pipette. Our new method allows for efficient, reliable, and automated guidance of both probes to the same neural structure with micron resolution. We also describe a new dataset of paired-recordings, which is available online. We propose that our novel targeting system, and ever expanding cross-validation dataset, will be vital to the development of new algorithms for automatically detecting/sorting single-units, characterizing new electrode materials/designs, and resolving nagging questions regarding the origin and nature of extracellular neural signals.

Rational design of graphene/porous carbon aerogels for high-performance flexible all-solid-state supercapacitors

2014 ◽  
Vol 2 (28) ◽  
pp. 10895-10903 ◽  
Author(s):  
Hong-Fei Ju ◽  
Wei-Li Song ◽  
Li-Zhen Fan
Keyword(s):  
Solid State ◽  
Porous Carbon ◽  
High Performance ◽  
Rational Design ◽  
Electrode Materials ◽  
Carbon Aerogels ◽  
Cycle Stability ◽  
Green Process ◽  
Excellent Electrochemical Performance

Graphene/porous carbon aerogels were rationally designed by a simple green process, exhibiting excellent electrochemical performance and long-term cycle stability as the electrode materials in flexible all-solid-state supercapacitors.

scholarly journals Identifying high performance and durable methylammonium-free lead halide perovskites through high throughput synthesis and characterization

2021 ◽  
Author(s):  
Yu An ◽  
Carlo Andrea Riccardo Perini ◽  
Juanita Hidalgo ◽  
Andrés-Felipe Castro-Méndez ◽  
Vagott Jacob N. ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Tolerance Factor ◽  
Structure Property ◽  
Term Operation ◽  
Wide Range ◽  
Holistic Understanding ◽  
Compositional Space ◽  
Tolerance Factors

One of the organic component in the perovskite photo-absorber, the methylammonium cation, has been suggested to be a roadblock to long-term operation of organic-inorganic hybrid perovskite-based solar cells. Methylammonium-free perovskites thus represent a possible direction for more stable photo-absorbers that are also compatible with multijunction solar cells. However, most work on methylammonium-free perovskites involves cesium and formamidinium as the A-site cations, which are thermodynamically less stable than the methylammonium-based materials. In this work we systematically explore the crystallographic and optical properties of the compositional space of mixed cation and mixed halide lead perovskites, where formamidinium (FA+) is gradually replaced by cesium (Cs+), and iodide (I-) is substituted by bromide (Br-), i.e., CsyFA1–yPb(BrxI1–x)3. The crystal phases, which could be tuned by changing the tolerance factor for mixed perovskite alloys, are qualitatively determined and the composition–structure relationship is established in the CsyFA1–yPb(BrxI1–x)3 compositional space. We find that higher tolerance factors lead to more cubic structures, whereas lower tolerance factors lead to more orthorhombic. We also find that while some correlation exists between tolerance factor and structure, tolerance factor does not provide a holistic understanding of whether a perovskite structure will fully form. Given the wide range of bandgaps produced by this compositional space, an empirical expression is devised to predict the optical bandgap of CsyFA1–yPb(BrxI1–x)3 perovskites – which changes as a function of composition –, conducive to the design of absorbers with bandgaps tailor-made for specific tandem and single-junction applications. By screening 26 solar cells with different compositions, we find that Cs1/6FA5/6PbI3 delivers the highest efficiency and long-term stability among I-rich compositions. This work sheds light on the fundamental structure-property relationships in the CsyFA1–yPb(BrxI1–x)3 compositional space, providing vital insight to the design of durable perovskite materials. Our approach provides a library of structural and optoelectronic information of this compositional space.

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