After various breadboard experiments with energy harvesters, I started free-forming them as can be seen in the picture below:

Free forming a circuit is an art in itself to me, because you are creating a shapable 3D artifact that is constrained by the functionality (the circuit). As such it is similar to other art forms like sculpting, carving or painting. There is a lot of freedom in how to shape the 3D circuit, that is fun to explore.