Interface I investigates the boundary between two interacting systems rendered into the physical. Each system is a compound of motors, strings and elastic bands arranged horizontally. The two units face each other vertically (one on the top, one on the bottom). Each motor of one level (top, bottom) is connected to its opponent with a string, meeting in the center. Both motors pull their string in the opposite direction (like in a tug of war). At the junction of the strings, a mesh of elastic bands connects the string to its neighbours. The mesh couples each element to its surrounding elements in order to achieve a local emergent behaviour.