Geometry dependent application of stretchable printed antenna

With the growing presence of wearable systems with ever increasing number of sensors, the need to embed the sensory information into communication systems is also increasing. Further, the seamless integration of sensors into fibres is needed to overcome the current wire-based connections, which easily break due to movements and deformations [1] . These challenges can be overcome by printing wireless communication devices directly on fabric or weaving the conducting fibres in such a way that they finally lead to devices such as antenna [2] [3] . Moreover, the antenna could act as sensor as well as data communication device [4] . For example, the shift in the resonant frequency of an antenna printed on stretchable substrate could indicate strain and hence can be used as strain sensor [5] . Further, different outcomes are possible by changing the geometry of antenna. Here we investigate this interesting direction through serpentine and linear shape dipole antenna printed on stretchable substrate. We compare the performance of conventional printed dipole antenna with serpentine-shape dipole, both realized by stencil printed stretchable silver paste on PDMS substrate. Results show that the serpentine geometry not only guarantees better electromechanical response, but also ensures a stable resonant frequency under stretching conditions (up to 20% strain). On the contrary, the resonant frequency of linear-shape dipole shifts linearly in response to the applied strain, with a sensitivity of -1.3 GHz/strain. Thus, while the antenna with serpentine configuration is suitable for wireless data transmission only, the linear dipole antenna is suitable for both strain sensing and wireless data transmission.