A study conducted by Ko Kugimoto et al. was published in the Applied Thermal Engineering.
In vacuum environments such as the lunar surface, heat cannot be removed by convection, making radiative cooling to deep space the only viable dissipation method. However, large radiator panels impose strict constraints on launch mass and stowage volume. Previous deployable radiators using shape memory alloys or pump-driven systems have addressed compact storage, but at the cost of increased power consumption, mechanical complexity, and potential reliability issues.
In this study, we developed a smart inflatable radiator that autonomously modulates its radiative area by exploiting vapor-pressure changes of a working fluid in response to temperature. The balance between vapor expansion force and a constant-force spring enables passive deployment and retraction without external power or active control. Vacuum experiments showed automatic deployment at approximately 34 °C, increasing heat dissipation from 26.6 W to 40.2 W under the same inlet temperature condition. Using a lumped-parameter thermal model, the system is projected to achieve 253 W/m² on the lunar surface—about 86% of the theoretical maximum.
These results suggest this fully passive, structurally self-supporting concept offers a lightweight and energy-efficient solution for future lunar and deep-space thermal management.
Title: Smart Inflatable Radiator for Autonomous, Temperature-driven Heat Dissipation
Authors: Kugimoto, K., Hirai, T., Kaneko, T.
Journal Name: Applied Thermal Engineering
Published: October 30, 2025
https://doi.org/10.1016/j.applthermaleng.2025.128860