Tuchfühler / touching silk
A silk cloth hangs from the ceiling of the room all the way to the floor. As people move through the space the air surrounding them also moves, in turn causing the cloth to move.
Behind the cloth is a group of electromechanical units. Each unit has a motor which moves a thin carbon fibre rod. First the rod gently approaches the cloth and in doing so, slides through two steel tubes which are electrically isolated from one another. If the rod comes into contact with the cloth, it will slightly bend. By bending, the rod connects the two steel tubes and thus completes an internal signal circuit. This causes the rod to move back away from the cloth for a moment.
The silk cloth is also transformed by the touch of the rod. The retreat of the cloth stimulates the surrounding units to approach it again, and thus transforming it further. So the attempt to determine the position of the cloth in space leads to a perpetual interplay of the observers.