Impedance Detection

Electrical and fluidic interconnections to the chip are made using a custom built connection block, machined from PEEK polymer. Fluidic and electrical connections are made by clamping the chip within the block. Spring loaded connectors are used to make contact with the chip electrodes and miniature 0-rings used to seal the fluidic connection between the block and chip. Microfluidic tubing and connectors are used to connect the PEEK block to the sample, waste and wash reservoirs. The connector block is mounted on a PCB which has the impedance detection circuitry and the... [Pg.515]

Sampling has to be frequent enough to mecisure the area of the peak as accurately as possible. A greater sampling rate than necessary does not improve reproducibility but impedes detection of the beginning and end of the peak and merely overloads the computer. [Pg.152]

Impedance electrodes have also been investigated as detectors for microchip microdialysis applications. An on-chip microdialysis system with inline sensing electrodes for impedance detection was developed [41], Cr/Au electrodes were used to determine the electrical resistance of changes in the concentration of phosphate-buffered saline (PBS) solutions that were used to characterize the system. The system monitored concentration changes with a 210-s system response delay. The lag time was attributed to dead volume in the tubing between the syringe pumps and the microsystem. [Pg.1334]

Min, M., Parve, T, Pliquett, U., 2014. Impedance detection. In Springer Encyclopedia of Microfluidics and Nanofluidics, second ed. Springer-Verlag, Heidelberg. [Pg.540]

Yu, T.H., Liu, J., Zhou, Y.X., 2004. Using electrical impedance detection to evaluate the viability of biomaterials subject to freezing or thermal injury. Anal. Bioanal. Chem. 378, 1793—1800. [Pg.547]

Bioimpedance detection Capacitive detection Conductance detection Dielectric detection Electrical impedance detection Electrochemical impedance detection... [Pg.1338]

Impedance Detection, Fig. 3 Paths of current flow (a) and electrical equivalent (b) of the impedance of cells (a) Paths of current flow in cell suspension, in which te is an extracellular resistance caused by the conductivity of... [Pg.1340]

Impedance Detection, Fig. 4 Vector diagrams of a resistance R, a capacitance C, and a constant phase element CPE... [Pg.1340]

Impedance Detection, Fig. 5 Vector diagram of a resistance R and a capacitance C, connected in series... [Pg.1341]

Impedance Detection, Fig. 7 Principles of impedance measurement case 1 - voltage excitation and current monitoring... [Pg.1342]

Impedance Detection, Fig. 10 Measurement of the impedance as a transfer function - imperfect voltage excitaticm... [Pg.1343]

Impedance Detection, Fig. 11 A system for measurement of components of the complex impedance ZQm)... [Pg.1344]

Impedance Detection, Fig. 12 Generalized structure of an impedance spectroscopy device using Fourier analysis for the processing of response signals... [Pg.1344]

Impedance Detection, Fig. 13 A multisine signal with 4 sine wave components at frequencies fj, 3fi, 5fi, and 7fi in two cases of initial phases (a) All have the same value of 90° - the peak value Is equal to 4 (k = 4) and... [Pg.1346]

Impedance Detection, Fig. 14 Optimal crest factors (CF) depending on the mmiber k > 5 of frequency components fj, 2fi,3fi,4fi,...,16fiinthe multisine signal the level CF = 1.414 corresponds to the crest factor of a single sine wave signal (k = 1)... [Pg.1346]

Impedance Detection, Fig. 15 An initial segment (200 is) of a linear chirp waveform with unit amplitude (A = 1), duration Tch = 2 s, and bandwidth Bexc, which covers 1 tolOO kHz... [Pg.1347]

Impedance Detection, Fig. 16 Normalized RMS (root-mean-square) spectral dcmsity distribution of the chirp signal presented in Fig. 15 ... [Pg.1347]

Impedance Detection, Fig. 17 Two methods for impedance spectroscopy using fast Fourier transform (FFT) (a) Through transforming of cross-correlation function (b) Through dividing of transformed lesptmse and excitation signals... [Pg.1348]

Impedance Detection, Fig. 18 Amplitude spectrum of the droplet impedance measured using two sequential chirp excitations covering 10 kHz to 1 MHz (blue) and 1-10 MHz (red)... [Pg.1348]

Impedance Detection, Fig. 19 A structure of a microfluidic device with chirp waveform excitation... [Pg.1348]

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