Low-Power Solar Sail Control using In-Plane Forces from Tunable Buckling of Kirigami Films

TL;DR

This paper addresses attitude control for solar sails with minimal power and mass by generating tunable in-plane light-pressure forces using buckled kirigami perforations. It combines finite element analysis of buckling with ray optics to predict oblique light reflection and resulting in-plane forces, showing that the net in-plane force aligns with the applied tensile strain and depends on unit-cell geometry, with a maximum normalized value around $0.34$ for certain designs. The authors validate the concept experimentally by observing oblique reflections from a stretched kirigami film illuminated by a laser, finding qualitative agreement with simulations. Overall, the study suggests a scalable, low-power method for sail steering that can be rapidly actuated with minimal mechanical complexity, offering an alternative to traditional rotating or vane-based attitude control systems.

Abstract

We present a proof-of-concept study showing that buckled aluminized polyimide films perforated with millimeter-scale cuts can redirect normally incident light obliquely and generate net in-plane force components parallel to the global solar sail surface. We use finite element simulations to obtain the buckled shapes of different periodic unit cell geometries and apply ray optics modeling to compute the resulting light-pressure forces. The simulations show that the buckled kirigami surfaces reflect light into different directions producing a net in-plane force parallel to the direction of stretching. We verify these trends experimentally by illuminating a tensioned kirigami sample with a laser and observing reflected beam patterns consistent with the ray optics simulations. These results suggest that kirigami films may offer a scalable, low-power, and lightweight way to achieve controllable in-plane forces for solar sail steering.

Figures (5)

• Figure 1: (a) A schematic diagram of the unit cell geometry aldan2025kirigamifilmreflectordeployable; (b) an example of the simulated shape of the buckled unit cell under tensile strain applied in the x-direction with the dotted line showing the normal to the surface, $\boldsymbol{n}$, at an arbitrary point on the unit cell, and arrows showing the directions of the incident and reflected rays, $\boldsymbol{r}_i$ and $\boldsymbol{r}_r$, respectively; (c)--(d) the laser-cut 7.8 $\mu\text{m}$ thick aluminized polyimide film in the (c) undeformed and (d) buckled states.
• Figure 2: (a) An oblique view on the simulated deformation of the periodic unit cell with $s_{\text{axial}}=s_{\text{diag}}=s=0.3~mm$ and $l_{\text{axial}}=9.3~mm$ under varying strains; (b)--(d) for each corresponding strain, the central unit cell in the periodic array consisting from 3$\times$3 to 7$\times$7 unit cells is illuminated by a light source having the same size as the unit cell. The diagrams show the simulated incident, reflected, and transmitted rays in the $\boldsymbol{r}_i$, $\boldsymbol{r}_r$, and $\boldsymbol{r}_t$ directions, respectively, with color indicating the normalized ray power which is defined as a ratio of the ray power after and before interaction with the unit cell. In all shown views, the light is incident in the negative z-direction and stretching is applied in the x-direction.
• Figure 3: (a) A side view on the simulated ray trajectories with arrows showing the directions of the generated net in-plane component of the force, $F_{\text{x, net}}$, and net out-of-plane component of the force, $F_{\text{z, net}}$, due to light with the total power of $P_{\text{inc}}$, and the inset enlarging a simulated array of periodic unit cells located in the xy-plane with $l_{\text{axial}}=9.3~mm$ and $s=0.3~mm$ under 8% tensile strain applied in the x-direction; (b) the magnitude of the simulated generated net force components as a function of strain for the unit cell in (a) when $P_{\text{inc}}=1~W$; (c) simulated normalized net in-plane force defined as $F_{\textit{in-plane, norm}}=cF_{\textit{x, net}}/P_{\textit{inc}}$ for stretched unit cells with varying geometric parameters $l_{\text{axial}}=9.3~mm$ and $s=0.3~mm$ (black), $l_{\text{axial}}=4~mm$ and $s=0.2~mm$ (red), and $l_{\text{axial}}=3~mm$ and $s=0.3~mm$ (blue); (d) corresponding simulated actuation force divided by the film width as a function of strain for periodic unit cells in (c).
• Figure 4: Photographs of the (a) side view on the experimental setup from the wall 2 perspective showing the normally illuminated region on the stretched sample, transmitted beams, and reflected beam spots located only on wall 1; and (b) front view from the wall 3 perspective showing the shape of reflected beam spots on the wall 1 and no beam spots on wall 2. The wall 1 was $\sim$26 cm wide, $\sim$31 cm tall, and $\sim$11 cm away from the illuminated region on the sample. Note: the grey edges at the intersections between adjacent walls were added manually to make the walls easier to distinguish.
• Figure 5: (a) Photographs of the perforated 7.8 $\mu\text{m}$ thick aluminized polyimide film with $l_{\text{axial}}=3~mm$ and $s=0.08~mm$ under varying tensile strains applied in the horizontal direction with normally illuminated half-unit cell; (b) photographs showing the shape and location of the reflected beam spots on the wall 1 under the same strains; (c) corresponding simulated beam spots with the blue marks indicating the location of the array of buckled unit cells at the same strains and the black rectangles representing the simulated wall 1 having the same size and located at the same distance from the illuminated spot as in the experiments. Note that in (c) at 10% and 20% strain, the simulations indicate additional beam spots located in the same plane as wall 1 but bellow the sample. These spots were not captured in the experimental photographs shown in (b) because the sample was positioned directly on a solid board tinted black.