V13_Electrical Impedance Spectroscopy in Microfluidic Systems

Play an AI-generated podcast conversation about this lesson

What is the primary function of the electrodes in the microfluidic EIS sensor described in the text?

To generate an electric field within the flow channel
To control the flow rate of the sample fluid
To provide a surface for the immobilization of biomolecules
To measure the electrochemical impedance of the sample fluid (correct)

How does the electrical double layer at the electrolyte-electrode interface affect the electrochemical impedance measured by the EIS sensor?

The double layer capacitance is negligible compared to the Faradaic impedance, so it has little effect on the overall impedance
The double layer capacitance dominates the overall impedance, making the sensor less sensitive to changes in the sample fluid
The double layer capacitance is constant, so it does not affect the measured impedance at all
The double layer capacitance varies with the composition of the sample fluid, leading to changes in the measured impedance (correct)

According to the Nernst equation, how does the reduction potential of an electrochemical reaction depend on the concentrations of the reactants and products?

The reduction potential is inversely proportional to the ratio of product to reactant concentrations
The reduction potential is directly proportional to the difference between the product and reactant concentrations
The reduction potential is independent of the concentrations of the reactants and products
The reduction potential is proportional to the natural logarithm of the ratio of product to reactant concentrations (correct)

How can the microfluidic EIS sensor be used in bioMEMS applications?

The sensor can be used to detect the presence of specific biomolecules in a sample fluid by monitoring changes in the electrochemical impedance (D) Signup and view all the answers

What is the purpose of the flow channel in the microfluidic EIS sensor?

To allow the sample fluid to flow over the electrodes, enabling real-time impedance measurements (A) Signup and view all the answers

How does the design of the microfluidic EIS sensor, with the electrodes embedded in the channel wall, affect the measurement of electrochemical impedance?

It increases the sensitivity of the sensor by maximizing the contact area between the electrodes and the sample fluid (C) Signup and view all the answers

What is the Poisson ratio of ZP material used in the context?

0.04 (C) Signup and view all the answers

In Electrical Impedance Spectroscopy, what is the significance of a high Rhyd.2 compared to Rhyd.1?

Suggests higher charge transfer resistance (C) Signup and view all the answers

What is a drawback of Microscopic control in the context of microfluidic systems?

Bad contrast on transparent ZP (D) Signup and view all the answers

Which technique is suggested in the text for easy cell handling in EIS with µF?

Micropipette Aspiration Technique (C) Signup and view all the answers

What does a low resolution due to curved glass surfaces imply in EIS according to the text?

Observer-dependent readout method (A) Signup and view all the answers

In the context of Microfluidic Systems, what does 'bad contrast (transparent ZP)' suggest as a challenge?

Low resolution (A) Signup and view all the answers

What is the main function of microelectrodes in microfluidic systems related to temperature?

Heating and cooling (B) Signup and view all the answers

In the context of microelectrodes, what does the term 'passivation layer' refer to?

Layer to protect the electrode from unwanted reactions with the electrolyte (B) Signup and view all the answers

Which process involves the deposition of a metal layer in microelectrodes?

Electroplating (A) Signup and view all the answers

What is a common application of microelectrodes in bio-MEMS?

Recording nerve signals (A) Signup and view all the answers

How do microelectrodes contribute to the field of electrokinetics within microfluidic systems?

Manipulating particle movement through an electric field (C) Signup and view all the answers

What is one of the methods used to fabricate microelectrodes?

Lithography, Electroplating, photo resist strip (C) Signup and view all the answers