Engineers at the University of Pennsylvania have engineered a durable thermal insulator by stacking hundreds of ultra-thin sheets of Mylar, creating a flexible material designed to withstand the extreme temperature swings and mechanical stresses of future lunar habitation.
Stacking Familiar Polymer Films for Extreme Environments
Establishing a long-term presence on the moon requires solving engineering challenges that rarely trouble builders on Earth. Lunar surface temperatures swing dramatically from hundreds of degrees below zero to boiling. At the same time, any materials shipped to the lunar surface must survive the physical realities of transport, handling, and construction.
Researchers at the University of Pennsylvania tackled this dual demand by turning to polyethylene terephthalate, commonly known as Mylar. Familiar as household food wrap and emergency blankets, Mylar is a form of polyethylene terephthalate, a plastic processed into thin, strong sheets that already appears in packaging and aerospace equipment, making it a familiar starting point for experiments.
Laboratory Durability Tests Under Heavy Compressive Stress
Insulation designed for vacuum environments typically forces a difficult design compromise. The ideal material is both resistant to damage and to the loss of heat.
To overcome this trade-off, the team assembled hybrid layered insulating film stacks, or HyLIFS, as described in a new paper in ACS Applied Materials & Interfaces published on September 16, 2026. In separate durability experiments, researchers repeatedly compressed stacks to 20 megapascals, far above the loads used for the thermal measurements. The applied stress was roughly equivalent to one atmosphere of pressure, a relevant scale for pressurized habitats.
“The combination of thermal and mechanical robustness is critical for long-term use on the moon,” notes first author Danielle R. Levin, a recent Penn doctoral graduate in chemistry, who also received a master’s in MEAM. “This material could open a pathway to inexpensive, durable and reusable lunar insulation.”
Danielle R. Levin, University of Pennsylvania
Alumina Coated Polymer Films Show Comparable Performance
The investigation also explored whether closely stacked polymer films could offer a useful combination of properties. Upon coating with alumina, however, the group’s medium-thickness specimens and their most successfully analyzed ultrathin films yielded comparable performance.
Because very thin plastic sheets frequently adhere to each other and foreign objects, processing and handling them becomes notably complicated. These particles protrude slightly from the film surface, creating microscopic points of contact between adjacent layers.
Questions remain about how the films would behave at larger scales, including whether they can survive multiple bending cycles as well as bumps and scuffs of real-life applications. Should the observed microscopic traits persist at greater scale, this substance might serve as essential pliable thermal protection for spacesuits, rovers, electronics, and lunar living quarters.
The ideal material is both resistant to damage and to the loss of heat.
Bargatin Lab, University of Pennsylvania
The study, titled Robust Layered Thermal Insulator Film Stacks for Vacuum Applications,
was supported by the National Science Foundation Division of Chemical, Bioengineering, Environmental and Transport Systems under grant number 1845933 and Penn Engineering. The authors declare no competing financial interest.