Kirigami Film Reflector for Deployable Space Antennas

TL;DR

This paper introduces a novel kirigami film reflector for space antennas that is lightweight, stretchable, and maintains high reflectance, enabling lighter deployable structures with reduced pretension requirements.

Contribution

It presents a new kirigami pattern with diagonal cuts for space reflector surfaces, demonstrating improved stretchability, reduced pretension, and high reflectance at 10 GHz.

Findings

Achieved a pretension reduction to ~0.5 N/m, ten times lower than traditional reflectors.

Demonstrated >90% reflectance at 10 GHz under deployment strains.

Developed a lightweight, stretchable film suitable for large space reflectors.

Abstract

We propose a low-pretension reflective kirigami film as a material for the reflective surfaces of large deployable space reflector antennas with an operating frequency around 10 GHz. The kirigami cut pattern is based on the well-known rotating squares pattern but is augmented with diagonal cuts to enhance stretchability and allow control over the effective Poisson's ratio. Using finite element simulations, we analyzed how the geometric parameters of this pattern affected the reflectance of the film and the pretension required to resist thermal deformations. Tensile testing of selected designs, which are approximately half the weight of traditional metallic meshes, demonstrated a substantial reduction in the needed pretension to ~0.5 N/m and as low as ~0.1 N/m. Such low pretension represents an order-of-magnitude improvement over traditional metallic mesh reflectors and could enable the use of lighter antenna trusses. Free-space reflectance measurements also show that these perforated films can maintain power reflectance exceeding 90% at 10 GHz under the strains expected in the deployed configuration.