Most batteries use two different materials and an electrolyte solution to create an imbalance of charge and thus a voltage. When the terminals of the battery are connected with a wire, this voltage produces a current.
In this Snack, the thin film of sweat on your hands acts like an electrolyte solution and reacts with the copper and aluminum plates. When you touch the copper plate, a reaction happens that uses electrons. When you touch the aluminum plate, a reaction happens that releases electrons.
Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, or even use Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for MakeCode, CircuitPython, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.