3D Printed Active Origami Dielectrics for Frequency Tunable Antennas Through Mechanical Actuation

Abstract

The possibility of using a reconfigurable metamaterial structure based on high permittivity dielectric elements in a flexible origami framework to control the electromagnetic response of a suspended patch antenna is investigated. Two different modular origami-inspired dielectric structures are fabricated by additive manufacturing and their insertion in the air gap of a suspended patch antenna is shown to modify the patch resonant frequency, originally designed to operate at approximately 1 GHz. Fused filament fabrication is used to manufacture dielectric origami using a ABS-30 vol% BaTiO₃ filament with a dielectric permittivity of ~11 to produce dielectric elements that are then connected by flexible hinges. A second structure is composed of a flexible, polymeric origami lattice manufactured by stereolithography containing inserted dielectric elements of ABS-60 vol% CaTiO₃ manufactured by field assisted sintering and with permittivity of ~18. Tunablity is achieved by different configurations of the dielectric origami, actuated by hand or mechanically, which varies the density of the dielectric origami and thus its effective permittivity and the patch resonant frequency. The dielectric origami structures provide a tunable range up to ~14% in good agreement with numerical simulations. Simulations were also used to show how a broader tunability range can be achieved easily, for example, by optimizing the size of the dielectric elements. Overall, the results from the preliminary dielectric origami structures shown here, enabled by advances in multi-material additive manufacture, suggest that the approach offers a wide design space with the potential to realise novel antenna functionality and flexibility.