For my speakers, I decided to work with known substrate and conductive material such as conductive copper tape and paper. However, I tested different patterns.
Speaker 2 + pressure sensor
This pattern requires covering a larger surface with magnets to be as successful.
1) Finish your heating circuit
2) Construct at least 2 test heating elements.
3) Measure their resistance, then use Ohm’s law to determine the proper power source. Test them with your thermochromic swatches and heat circuit.
4) Construct a mini-project that reveals an embedded message, pattern, or behavior using thermochromic ink.