Conducting Polymer Switches Permit the Development of a Frequency-Reconfigurable Antenna

Abstract

Conjugated polymers (CPs) undergo a wide range of reversible intrinsic property changes including electrical conductivity, electromagnetic absorption, volume, and charge mobility upon electrochemical oxidation/reduction, which has made them popular as ON/OFF organic-based switchable materials. Recent studies on the insulating-to-conductive transition within CPs have paved the way for a next generation of flexible switches that permit the creation of “dynamic” electric circuits. Here, we present an approach to a low-voltage, low-power electrochemically controllable, switchable, and printable CP-based conductive element that acts as a platform for the configuration of frequency-reconfigurable radiative antennas. We demonstrate that the DC conductivity of a soluble PEDOT derivative, PE2, film can be switched electrochemically by 4 orders of magnitude across large insulating gaps up to 15 mm within 20 s. Its integration in a DC switching element that is incorporated along the poles of a half-wave dipole antenna structure is able to generate an AC resonant frequency switch, and thus a radiation frequency shift, in the microwave (i.e., 1–2 GHz) range. This type of printable antenna fills an important need for the demand of bandwidth that is growing beyond the crowded frequency spectrum, by relying on the development of frequency-reconfigurable antenna systems capable of dynamically tuning their spectral properties when desired.