Characterization of stretchable serpentine microwave devices for wearable electronics

Serpentine interconnects, made stretchable by patterning copper traces into serpentine mesh geometries, are attractive for applications in wearable electronics. This paper studies the suitability of these structures for wireless devices at microwave frequencies, where the sub-wavelength dimensions of the serpentine pattern contribute to changes in electrical length and propagation loss. The effects of converting solid metal traces to serpentine geometries are quantified for microwave transmission lines and dipole antennas. In addition, the effects of stretching are characterized and measured for a fabricated dipole antenna.