In this paper, we describe and identify current limitations of wearable user interface to elicit requirements and design considerations of an effective wearable user interface framework. Based on the elicited criteria, we propose a novel wearable user interface framework that succinctly enables expressive physical contacts to be made on a sensor-embedded wristband of the wearable device. In the presented framework, multiple force-sensitive linear potentiometers enclosed in the wristband are exploited as tools of user input where an instance of user contact is represented as a pairwise set of a contacted position with an exerted force value at that position. Consequently, the proposed framework expands input expressivity of the wearable device by creating and recognizing various position-force combinations of user input. Moreover, to help user differentiate and navigate different inputs, two novel methods of instant N-ary input and indicative visualization are integrated into the framework, respectively. To demonstrate the feasibility of the proposed conceptual framework, a proof-of-concept text entry application is implemented and evaluated.
['Hyoseok Yoon', 'Ji-Eun Lee', 'Seho Park', 'Kyung-Taek Lee']
Position and Force Sensitive N-Ary User Interface Framework for Wrist-Worn Wearables