Differential C4D sensor for conductive and non-conductive fluidic channel

Determination of Biogenic Amines in Seawater Using Capillary Electrophoresis with Capacitively Coupled Contactless Conductivity Detection

“…The initial electrophoretic conditions with C 4 D used were adopted from the work of Gong & Hauser [ 18 ] and Li et al [ 4 ], who achieved the separation of the eight BAs using 150 mmol L −1 , 18-crown-6 in 500 mmol L −1 acetic acid as the BGE. Thirty minutes of preconditioning and equilibrium time between every two injections was required.…”

“…In this study, different types of weak organic acids were studied, including monocarboxylic acids (formic, acetic and propionic), dicarboxylic acids (oxalic and malonic), tricarboxylic acid (citric), unsaturated dicarboxylic acid (maleic) and hydroxyl dicarboxylic acids (malic and tartaric). These acids were selected based on their solubility in water and low conductivity to ensure high baseline stability [ 18 ]. Most of these acids succeeded in achieving the goal of ionization, but unluckily, did not result in satisfactory separation of all of the BAs.…”

Numerical calculation and analysis of a novel complex impedance sensing approach for in-flow droplet detection utilizing the C4D technique

“…The detection of objects in the fluidic channel plays an important role in many applications, such as pharmacology, biology, analytical chemistry, food analysis, water quality testing, medical [19][20][21][22], and especially cell culture [23,24]. Several methods have been proposed and developed for object detection in fluidic channels, such as optical, ultrasonic, and electrical sensors based on conductive and non-conductive mechanisms [22,25,26].…”

“…This study presents the conventional C 4 D structure utilizing a novel impedance sensing approach for in-flow micro-droplet analysis and electrical characteristics of the fluidic channel. Impedance sensing approaches are usually considered to be effective methods in fluidic flow detection measurement, mainly due to their advantages of fast response, high dynamic range, and sensitivity, which can be used in invasive or non-invasive measurements [20,[35][36][37][38][39][40]. A two-electrode non-contact capacitive sensor was proposed and investigated to verify the performance of detecting foreign objects in the fluidic flow and provide information about the electrical characteristics of the fluidic channel.…”

“…The detection and classification of micro-particle in the fluidic channel or the impurities in the fluidic flow is very important. Some useful applications of the C 4 D sensor architecture are the velocity estimation of a fluid flow [20], and volume detection of bubbles in the blood circuit of hemodialysis by morphological image processing [41,42]. Besides, the use of the C 4 D technique in detecting impurities and estimating their velocity in the fluidic channel has been studied and developed by many research groups but encountered some difficulties and limitations [43,44].…”