PenShaft: Enabling Pen Shaft Detection and Interaction for Touchscreens

PenShaft is a battery-free, easy to implement solution for augmenting the shaft of a capacitive pen with interactive capabilities. By applying conductive materials in a specific pattern on the pen’s shaft, we can detect when it is laid on a capacitive touchscreen. This enables on-pen interactions, such as button clicks or swiping, and whole-shaft interactions, such as rotating and dragging the stylus. PenShaft supports at least six interactions, freeing the pen from having to interact with the layers or menus of a conventional user interface. We validate a device’s capability to detect these six interactions with all but two interactions achieving a success rate above 95%. We then present a series of applications to demonstrate the flexibility and utility of these interactions when using the pen.