GraspZoom: zooming and scrolling control model for single-handed mobile interaction

A pressure sensing based single-handed interaction model is presented in this paper. Unlike traditional desktop GUI model, mobile UI model has not been established yet. For example, Apple iPhone proposed "Pinch" operation, which use two fingers to zoom-in and zoom-out objects. However, in a today's hand-held situation, manipulation methods using two fingers are not always good solution because they require two hands in order to hold the device itself in most cases. We propose a single-handed UI scheme "GraspZoom": multi-state input model using pressure sensing. Force Sensitive Resistor (FSR) attached on backside of a mobile phone was employed in order to evaluate effectiveness of pressure based control model. We also describe example applications which enable intuitive and continuous zooming and scrolling. By using tiny thumb gesture input along with this pressure sensing method, bi-directional operations (e.g., zoom-in and -out) are also achieved.