TouchShield: a virtual control for stable grip of a smartphone using the thumb

People commonly manipulate their smartphones using the thumb, but this is often done with an unstable grip in which the phone lays on their fingers, while the thumb hovers over the touch screen. In order to offer a secure and stable grip, we designed a virtual control called TouchShield, which provides place in which the thumb can pin the phone down in order to provide a stable grip. In a user study, we confirmed that this form of control does not interfere with existing touch screen operations, and the possibility that TouchShield can make more stable grip. An incidental function of TouchShield is that it provides shortcuts to frequently used commands via the thumb, a function that was also shown to be effective in the user study.