Copper and zinc plates connected by micro-ammeter; your hand completes the circuit.
Clean copper and zinc sheet metal stock is cut into strips or pads. Alligator clip a zinc strip and a copper strip and plug the leads into a modern multimeter. DC 2V scale should cover the 1.09V that we expect from a zinc/copper battery at standard conditions of 1 Molar electrolyte and room temperature.
Our fingers are a network of electrolytic conductors, with more or less conductance (depending on moisture and salt). Pressed to the metal strips, adjacent fingers complete the circuit and...
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