MultiKnob — A Knob for Multiplexing Rotation Inputs by Multitouch-based Grasp Recognition

Rotary knobs are used on many devices. However, while we enrich the functionalities of smart devices, controlling such functionalities by using the rotation as sole input appears to be rather limited. Therefore, we created a physical rotary controller which enriches the input capabilities of a rotary knob, called MultiKnob. It takes the count of applied fingers as an input parameter for multiplexing rotation. The paper discusses three iterations of our prototyping: Beginning with an attempt to extend an existing rotary controller using conductive paint, to the development of several conductive 3D printed prototypes for use on a smartphone display, to a cylinder sensing multi-touch based on infrared light. We discuss possible applications and limitations of a knob which allows to recognize a user’s grasp.