MimicTile is a novel variable stiffness deformable user interface for mobile devices that implements two key features. The first feature is an input interface that accepts a variety of deformation-based gestures, providing a user with several ways of interacting with a small mobile device. The other feature is the ability to provide information to the user through haptic feedback by varying the stiffness of the interface. The features are suitable for enhancing mobile applications. They were implemented using only shape memory alloy (SMA) wires as the actuator. SMA wire is extremely flexible, making it ideal for deformable user interfaces. In MimicTile, SMA wires act as both actuators and external input sensors. The actuator function works by altering stiffness based on user input. This study also discusses ideas for further development of deformable user interfaces.