Smart textile -- textile which is conductive -- is one of promising materials for wearable interfaces. There are numbers of types of smart textile including conductive thread, piezo-resistive textile, etc. Depending on its composition, it can used as different sensors such as touch, pressure, stretch, humidity, inclination.
Because of it limited input methods, smart watches are being used by small percentage of smartphone users in spite of its mobility and multi sensors. To resolve this problem, we suggest a series of application scenario of smart armband connected to smart watch. Proposed smart armband is used as touch and stretch sensor. We test different types of smart textile and provide insight where to utilise them. In addition, we implement stretch sensory function of the armband and evaluate it.