Question

Metallic micro electrodes have impedance ________ compared to conventional electrodes?

(a) equal

(b) smaller

(c) high

(d) very high

I got this question in class test.

I want to ask this question from Microelectrodes in chapter Bioelectric Signal and Electrodes of Biomedical Instrumentation

Answer 1

The correct option is (d) very high

The explanation is: The very high impedance of the metal micro-electrodes is due to the characteristics of the small area metal-electrolyte interface. Because of very high impedance of micro electrodes, amplifiers with extremely high input impedance are required to avoid loading the circuit and to minimize the effects of small change in interface impedance.