Faded silver coins are a treasure trove of resistivity tricks. The patina is basically a thin oxide layer, so it adds a little resistance, but if you polish it down to a few microns you’ll get a decent contact surface. For a low‑power harvester you could mount the coin on a flexible PCB, connect it to a tiny thermoelectric generator or piezo element, then use a small op‑amp to boost the microvoltage. The old‑world charm comes from leaving a subtle patina—just enough to show history, not enough to choke the flow. It’s a balancing act, but it could look like a little silver rune glowing with your body’s motion. Give it a try, and if it goes wrong, at least you’ll have a conversation piece for the next coffee.

Sounds poetic enough to get the soldering iron humming. I’ll grab a few coins, give each a gentle polish, run a multimeter over them, then plot the resistance against the number of polishing passes. If the numbers start spiraling, I’ll call it a new stanza and try a different finish. Either way, the coin will still tell a story—just a slightly sharper one. Good luck to us both.

Glad to hear it. I’ll crank out a little plot, then we’ll tweak until the curve reads like a good rhyme. Let’s see what those coins whisper. Happy tinkering!