Comprehensive study of noise processes in electrode electrolyte interfaces

Abstract

A general circuit model is derived for the electrical noise of electrode-electrolyte systems, with emphasis on its implications for electrochemical sensors. The noise power spectral densities associated with all noise sources introduced in the model are also analytically calculated. Current and voltage fluctuations in typical electrode-electrolyte systems are demonstrated to originate from either thermal equilibrium noise created by conductors, or nonequilibrium excess noise caused by charge transfer processes produced by electrochemical interactions. The power spectral density of the thermal equilibrium noise is predicted using the fluctuation-dissipation theorem of thermodynamics, while the excess noise is assessed in view of charge transfer kinetics, along with mass transfer processes in the electrode proximity. The presented noise model not only explains previously reported noise spectral densities such as thermal noise in sensing electrodes, shot noise in electrochemical batteries, and 1/f noise in corrosive interfaces, it also provides design-oriented insight into the fabrication of low-noise micro-and nanoelectrochemical sensors.

Mass Transfer in the Electro-Dissolution of 90% Copper-10% Nickel Alloy in a Solution of Lithium Bromide

“…Mass Transfer in the Electro-Dissolution of 90% Copper-10% Nickel Alloy in a Solution of Lithium Bromide 511 information of a corrosive process; however, the signal as such masks phenomena occurring outside the charge transfer process (Hassibi et al, 2004). The diagrams ( Figure 5) show the behavior of the noise signal in current and potential in the time domain of copper-nickel alloy in the LiBr solution at different periods of exposure under static conditions at 25 °C.…”

Current Fluctuation Measurements of Amperometric Gas Sensors Constructed with Three Different Technology Procedures

“…The inherent noise sources are associated with conductive mechanisms in electronic devices. Thus, the fluctuations originate in amperometric sensors at the electrode/electrolyte interface where thermal agitation, diffusion and electrochemical reactions of mobile ions take place [33,34]. Only the thermal noise anticipates no current flow through the amperometric cell.…”

Modeling and Analysis of Low Frequency Noise in Ion-Field-Effect Transistors Sensors

“…The origin of noise in electrode-electrolyte systems can be divided into two categories, namely, the thermal equilibrium noise and non equilibrium noise [11] [22]. The thermal equilibrium fluctuations are the only source of noise in the equilibrium condition where as recombination and generation of charged particle is the main cause of the non-equilibrium fluctuation [11]. Modeling results shows that the 1/f noise is more significant at low frequencies f < 40 MHz, beyond the white noise that is dominant.…”

“…The source of this noise is probably defined as the Brownian noise which is believed to be originated from the electrode-electrolyte structure of the ISFET. The origin of noise in electrode-electrolyte systems can be divided into two categories, namely, the thermal equilibrium noise and non equilibrium noise [11] [22]. The thermal equilibrium fluctuations are the only source of noise in the equilibrium condition where as recombination and generation of charged particle is the main cause of the non-equilibrium fluctuation [11].…”

“…In several works [5] [10] [11], it is believed that the presences of 1/f low-frequency noise in ISFET sensors are mostly contributed by the FET structure of the device, which is dominated by the Insulator-Semiconductor interface [12]. More the pH-dependent 1/f electrochemical noise in ISFET is considered to be negligible in some device [4] [10].…”