2019 Volume 27 Pages 96-105
Although wearable interfaces can enable computer operation anywhere and at any time, many current devices are too cumbersome or socially unacceptable to wear in daily life. In contrast, a ridge of cloth produces a wrinkle that forms naturally on clothes, and the shape of these wrinkles can be recognized by their tactile sensations. Hence, they can achieve eye-free input and output functions. We therefore propose an interface that uses the wrinkles on clothes to input and output information. The interface generates several wrinkles on an item of clothing when an application requires input. The user senses the current state and number of choices by touching these wrinkles. The user can then input commands by selecting one wrinkle. The wrinkles disappear after the operation is complete. We implemented a prototype of this interface and investigated the social acceptance of the device position. The results show that the various device positions (excluding the armpit) achieve a moderate level of social acceptance. We mounted the prototype on the front of the right thigh of a pair of trousers and evaluated the recognition accuracy of the wrinkle patterns as well as the learning curve with respect to input accuracy and time. The participants achieved a recognition rate of 89.4%, input accuracy of 95% or more, and an input time of approximately 2s. This device has the potential to provide unobtrusive and eyes-free operation and the current results indicate directions for its future development.