Tunable Zeroth-Order Resonance in Metamaterial-Inspired Transmission Lines Based on Electrowetting on Dielectric

A new approach for tuning the resonant frequency of metamaterial-inspired transmission lines (TLs) by using electrowetting on dielectric (EWOD) is presented. Coplanar Waveguide (CPW) metamaterial-inspired TLs were designed and used as digital microfluidic platforms, where tunable resonance frequency was demonstrated for RF/microwave applications. A repeatable tuning mechanism was realized by exploiting the interface deformation of a liquid metal (mercury) droplet by an applied voltage. The maximum tuning range achieved is around 400 MHz (from 3.51 GHz to 3.92 GHz) with a dc actuation voltage of 110 V.