Impedance-Based Flow Rate Measurements in Microchannels of Low Young Modulus
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
MESS24 - Microelectronic Systems Symposium
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
We propose a sensor concept supported by Electrical Impedance Spectroscopy (EIS), aimed at measuring both the flow rate v and the conductivity ? of test liquids within a low Young's modulus microchannel. Impedance spectroscopy, commonly used in analyzing the electrical properties of materials, particularly solids or electrolytes, finds applications in diverse fields such as battery development, fuel cells, sensors, corrosion protection, and semiconductors. The sensor principle involves subjecting the liquid to a sinusoidal AC voltage and monitoring the resulting current response, generating complex impedance spectra. Establishing a connection between the measured data and the physical properties of the liquid typically involves employing an electrical equivalent circuit, which mimics the behavior of the real system as closely as possible. In our setup, we gauge both flow rate and conductivity by examining specific parameter variations in the system's equivalent circuit. The flow measurements fluctuate with conductivity ?, leading to distinct EIS responses at the same flow rate v. Consequently, alterations in either the flow rate or the conductivity affect the equivalent circuit's parameters. However, prior works have often overlooked changes in conductivity, or only measured conductivity at a fixed frequency f, thereby missing out on vital equivalent circuit parameter information obtained from the entire impedance spectrum. Simultaneously evaluating these parameters for both conductivity and flow rate can compensate the effects of different conductive liquids on the equivalent circuit parameters during flow rate measurements.
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