An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit. Electrodes are essential parts of batteries that can consist of a variety of materials depending on the type of battery.
An electrochemical cell is a device that generates electrical energy from chemical reactions. Electrical energy can also be applied to these cells to cause chemical reactions to occur. Electrochemical cells which generate an electric current are called voltaic or galvanic cells and those that generate chemical reactions, via electrolysis for example, are called electrolytic cells.
Microfluidics refers to a system that manipulates a small amount of fluids ( using small channels with sizes ten to hundreds micrometres. It is a multidisciplinary field that involves molecular analysis, biodefence, molecular biology, and microelectronics. It has practical applications in the design of systems that process low volumes of fluids to achieve multiplexing, automation, and high-throughput screening. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies.
Inductively coupled plasma mass spectrometry (ICP-MS) is a type of mass spectrometry that uses an inductively coupled plasma to ionize the sample. It atomizes the sample and creates atomic and small polyatomic ions, which are then detected. It is known and used for its ability to detect metals and several non-metals in liquid samples at very low concentrations. It can detect different isotopes of the same element, which makes it a versatile tool in isotopic labeling.
Electrophysiology is the branch of physiology that studies the electrical properties of biological cells and tissues. It involves measurements of voltage changes or electric current or manipulations on a wide variety of scales from single ion channel proteins to whole organs like the heart. In neuroscience, it includes measurements of the electrical activity of neurons, and, in particular, action potential activity. Recordings of large-scale electric signals from the nervous system, such as electroencephalography, may also be referred to as electrophysiological recordings. They are useful for electrodiagnosis and monitoring.
A biosensor is an analytical device, used for the detection of a chemical substance, that combines a biological component with a physicochemical detector. The sensitive biological element, e.g. tissue, microorganisms, organelles, cell receptors, enzymes, antibodies, nucleic acids, etc., is a biologically derived material or biomimetic component that interacts with, binds with, or recognizes the analyte under study. The biologically sensitive elements can also be created by biological engineering. The transducer or the detector element, which transforms one signal into another one, works in a physicochemical way: optical, piezoelectric, electrochemical, electrochemiluminescence etc., resulting from the interaction of the analyte with the biological element, to easily measure and quantify. The biosensor reader device connects with the associated electronics or signal processors that are primarily responsible for the display of the results in a user-friendly way. This sometimes accounts for the most expensive part of the sensor device, however it is possible to generate a user friendly display that includes transducer and sensitive element. The readers are usually custom-designed and manufactured to suit the different working principles of biosensors.
In electrochemistry, cyclic voltammetry (CV) is a type of potentiodynamic measurement. In a cyclic voltammetry experiment, the working electrode potential is ramped linearly versus time. Unlike in linear sweep voltammetry, after the set potential is reached in a CV experiment, the working electrode's potential is ramped in the opposite direction to return to the initial potential. These cycles of ramps in potential may be repeated as many times as needed. The current at the working electrode is plotted versus the applied voltage to give the cyclic voltammogram trace. Cyclic voltammetry is generally used to study the electrochemical properties of an analyte in solution or of a molecule that is adsorbed onto the electrode.
A potentiostat is the electronic hardware required to control a three electrode cell and run most electroanalytical experiments. A Bipotentiostat and polypotentiostat are potentiostats capable of controlling two working electrodes and more than two working electrodes, respectively.
Voltammetry is a category of electroanalytical methods used in analytical chemistry and various industrial processes. In voltammetry, information about an analyte is obtained by measuring the current as the potential is varied. The analytical data for a voltammetric experiment comes in the form of a voltammogram, which plots the current produced by the analyte versus the potential of the working electrode.
Nanoelectrochemistry is a branch of electrochemistry that investigates the electrical and electrochemical properties of materials at the nanometer size regime. Nanoelectrochemistry plays significant role in the fabrication of various sensors, and devices for detecting molecules at very low concentrations.
In analytical chemistry, a rotating ring-disk electrode (RRDE) is a double working electrode used in hydrodynamic voltammetry, very similar to a rotating disk electrode (RDE). The electrode rotates during experiments inducing a flux of analyte to the electrode. This system used in electrochemical studies when investigating reaction mechanisms related to redox chemistry and other chemical phenomena.
Bio-MEMS is an abbreviation for biomedical microelectromechanical systems. Bio-MEMS have considerable overlap, and is sometimes considered synonymous, with lab-on-a-chip (LOC) and micro total analysis systems (μTAS). Bio-MEMS is typically more focused on mechanical parts and microfabrication technologies made suitable for biological applications. On the other hand, lab-on-a-chip is concerned with miniaturization and integration of laboratory processes and experiments into single chips. In this definition, lab-on-a-chip devices do not strictly have biological applications, although most do or are amenable to be adapted for biological purposes. Similarly, micro total analysis systems may not have biological applications in mind, and are usually dedicated to chemical analysis. A broad definition for bio-MEMS can be used to refer to the science and technology of operating at the microscale for biological and biomedical applications, which may or may not include any electronic or mechanical functions. The interdisciplinary nature of bio-MEMS combines material sciences, clinical sciences, medicine, surgery, electrical engineering, mechanical engineering, optical engineering, chemical engineering, and biomedical engineering. Some of its major applications include genomics, proteomics, molecular diagnostics, point-of-care diagnostics, tissue engineering, single cell analysis and implantable microdevices.
Instrumental analysis is a field of analytical chemistry that investigates analytes using scientific instruments.
Scanning electrochemical microscopy (SECM) is a technique within the broader class of scanning probe microscopy (SPM) that is used to measure the local electrochemical behavior of liquid/solid, liquid/gas and liquid/liquid interfaces. Initial characterization of the technique was credited to University of Texas electrochemist, Allen J. Bard, in 1989. Since then, the theoretical underpinnings have matured to allow widespread use of the technique in chemistry, biology and materials science. Spatially resolved electrochemical signals can be acquired by measuring the current at an ultramicroelectrode (UME) tip as a function of precise tip position over a substrate region of interest. Interpretation of the SECM signal is based on the concept of diffusion-limited current. Two-dimensional raster scan information can be compiled to generate images of surface reactivity and chemical kinetics.
Droplet-based microfluidics manipulate discrete volumes of fluids in immiscible phases with low Reynolds number and laminar flow regimes. Interest in droplet-based microfluidics systems has been growing substantially in past decades. Microdroplets offer the feasibility of handling miniature volumes of fluids conveniently, provide better mixing, encapsulation, sorting, sensing and are suitable for high throughput experiments. Two immiscible phases used for the droplet based systems are referred to as the continuous phase and dispersed phase.
Paper-based microfluidics are microfluidic devices that consist of a series of hydrophilic cellulose or nitrocellulose fibers that transport fluid from an inlet through the porous medium to a desired outlet or region of the device, by means of capillary action. This technology builds on the conventional lateral flow test which is capable of detecting many infectious agents and chemical contaminants. The main advantage of this is that it is largely a passively controlled device unlike more complex microfluidic devices. Development of paper-based microfluidic devices began in the early 21st century to meet a need for inexpensive and portable medical diagnostic systems.
Electrochemical AFM (EC-AFM) is a particular type of Scanning probe microscopy (SPM), which combines the classical Atomic force microscopy (AFM) together with electrochemical measurements. EC-AFM allows to perform in-situ AFM measurements in an electrochemical cell, in order to investigate the actual changes in the electrode surface morphology during electrochemical reactions. The solid-liquid interface is thus investigated. This technique was developed for the first time in 1996 by Kouzeki et al., who studied amorphous and polycrystalline thin films of Naphthalocyanine on Indium tin oxide in a solution of 0.1 M Potassium chloride (KCl). Unlike the Electrochemical scanning tunneling microscope, previously developed by Itaya and Tomita in 1988, the tip is non-conductive and it is easily steered in a liquid environment.
Scanning vibrating electrode technique (SVET), also known as vibrating probe within the field of biology, is a scanning probe microscopy (SPM) technique which visualizes electrochemical processes at a sample. It was originally introduced in 1974 by Jaffe and Nuccitelli to investigate the electrical current densities near living cells. Starting in the 1980s Hugh Isaacs began to apply SVET to a number of different corrosion studies. SVET measures local current density distributions in the solution above the sample of interest, to map electrochemical processes in situ as they occur. It utilizes a probe, vibrating perpendicular to the sample of interest, to enhance the measured signal. It is related to scanning ion-selective electrode technique (SIET), which can be used with SVET in corrosion studies, and scanning reference electrode technique (SRET), which is a precursor to SVET.
Single-Entity Electrochemistry (SEE) refers to the electroanalysis of an individual unit of interest. A unique feature of SEE is that it unifies multiple different branches of electrochemistry. Single-Entity Electrochemistry pushes the bounds of the field as it can measure entities on a scale of 100 microns to angstroms. Single-Entity Electrochemistry is important because it gives the ability to view how a single molecule, or cell, or "thing" affects the bulk response, and thus the chemistry that might have gone unknown otherwise. The ability to monitor the movement of one electron or ion from one unit to another is valuable, as many vital reactions and mechanisms undergo this process. Electrochemistry is well suited for this measurement due to its incredible sensitivity. Single-Entity Electrochemistry can be used to investigate nanoparticles, wires, vesicles, nanobubbles, nanotubes, cells, and viruses, and other small molecules and ions. Single-entity electrochemistry has been successfully used to determine the size distribution of particles as well as the number of particles present inside a vesicle or other similar structures
The Iron Redox Flow Battery (IRFB), also known as Iron Salt Battery (ISB), stores and releases energy through the electrochemical reaction of iron salt. This type of battery belongs to the class of redox-flow batteries (RFB), which are alternative solutions to Lithium-Ion Batteries (LIB) for stationary applications. The IRFB can achieve up to 70% round trip energy efficiency. In comparison, other long duration storage technologies such as pumped hydro energy storage provide around 80% round trip energy efficiency.
