# Current density uniformity electrode array

1. Apr 2, 2015

### leonhart88

Hi All,

I'm working on a research project that requires putting an electrode array with 4 elements into a flexible tube filled with conductive liquid. The electrode array is a series of balls, with the first being positive and the last being negative. The idea is to measure the change in voltage between the innermost electrodes when the tube is deformed.

Deforming the tube changes the cross sectional area, thus changing the resistance between the two electrodes. Assuming a constant current is driven through, this means a proportional change in voltage. If the current density is perfectly uniform and the length between electrodes is constant, along with the resistivity of the media, I expect a linear response.

Linearity is not mandatory since we can always calibrate things, however, how can I be sure that the current density is uniform?

2. Apr 2, 2015

### Staff: Mentor

You cannot - if the tube is bent or something else (like electrode placement) disturbs the symmetry, current density won't be uniform. The deviations could be negligible, depending on the setup.