Transmitting analog voltages in neuromorphic circuits reminds me of a cool experiment I heard about a while ago. A team used an evolutionary algorithm to adapt an FPGA to recognize sounds. When they got the behavior they wanted, they tried copying the circuit to another FPGA and found that it didn't work because the algorithm had evolved dependencies on specific quirks in the original physical FPGA. I can't figure out how to link to the PDF directly, but the original research is probably "An Evolved Circuit, Intrinsic in Silicon, Entwined With Physics" by Adrian Thompson, which tells the story far better than I have.

It's neat to think that our own brains might have adapted wiring that works specifically for the actual molecules that make up our bodies. It's uniqueness on a different level.