Novel stretchable electrically conductive composites for tunable RF devices

Stretchable, flexible and tunable RF devices that are fabricated with Polydimethylsiloxane (PDMS) Electrically Conductive Composites (ECC) are presented. Using this composite material allows mechanical modulation of the device dimensions resulting in tuning of its frequency response. A planar loop antenna and a 5th order stepped impedance low pass filter operating around 1.5 GHz with tunability greater than 15% are shown. The ECC can reach an electrical resistivity as low as 10⁻⁴ Ω. cm, which is close to a metal resistivity. The materials are also ultra-low cost for massive fabrication. This technology opens the door for tunable RF devices on flexible and curvilinear packages.