Human skin conducts electricity and can serve as a variable resistor inside a circuit

Flesh conducts electricity: pressing a finger across circuit board traces adds a flesh-resistor in parallel with existing components, lowering net resistance and raising oscillator pitch or clock speed. Moisture increases conductivity. The performer’s body thus becomes a live, expressive control surface. Collins uses this to introduce the circuit-bending/laying-of-hands technique: you do not need to know what you’re doing to find a sweet spot; the feedback relationship between body and circuit is acquired through play. The technique generalises to any resistive material: coins, antistatic foam, fruits, even photocells — all are body-like controllers with different response characteristics.

Examples

Touch the circuit board of an open AM radio while it broadcasts white noise; find the point where the signal becomes an oscillator. Place a damp finger across a toy’s timing resistor to hear the clock speed up.

Assessment

Predict the direction of pitch change when a wet finger is pressed harder onto a toy’s clock circuit, and explain which rule of Ohm’s Law governs this. Then describe a more stable, repeatable substitute for the finger.