What is a voltage sensor ?
You can use wires to a an Arduino, and the Arduino can measure the voltage.
Or you can use small microcontrollers that measure the voltage and sent the data somehow to a computer or to an Arduino.
What size is it ?
Can you add many wires to it ? or will the weight of the wires be a problem ?
Sorry when I say voltage sensor, I am not referencing anything specifically, rather I just need to measure the voltage somehow.
As to adding wires, that was my second thought, but it is a small model, approximately 3cm x 3cm and it will likely be 3D printed or injection moulded. The weight of wires would not be a problem, rather their influence on the conductivity of the polymer would be a problem.
Do you have any spec for how many ohms per cubic unit your polymer is?
As far as electrical connections go there's probably not much more to this than jamming wires into the polymer and then connecting the other ends to analog pins on the Arduino. If you need more probes than your particular Arduino has analog inputs (e.g. the Uno has 6 inputs) then you'll need to add multiplexer chips like the 4051.
Best way to get started here is to provide a complete picture of what you're trying to do. Draw your polymer thing and show the wire connections (label/number the wires so they can be referred to). A picture drawn on paper and then snapped with a camera is plenty sufficient for the class of people we have around here. ;)
I have an uno and for the first version, 6 inputs should be fine. The resistivity of the polymer is approximately 6.5 ohms.m.
Thanks for the suggestions!