[Image above] Hiker enjoying the view in the Himalaya mountains. Credit: Olga Danylenko(opens in new tab) / Shutterstock
For many, the autumn months bring cozy routines and thoughtful reflections as the year comes to an end. But for hundreds of mountaineers(opens in new tab) each year, the autumn marks an ideal time(opens in new tab) to summit Mount Everest, when weather conditions stabilize again after the summer monsoon season.
The sport of mountaineering requires a lengthy list of equipment(opens in new tab). It not only requires the technical hardware required to scale the peaks, but it also includes navigation items, kitchen supplies, emergency first aid, health and hygiene kits, and another crucial category: clothing.
Selecting the optimal clothing for a mountain adventure is important because it regulates body temperature(opens in new tab) as exertion levels shift; wicks moisture away to prevent chills; and protects against the cold, wind, and precipitation. The basic layering formula includes base layers, light insulation, medium insulation, hard shells, and parkas, but ultimately, an insulation system will depend on the specific conditions faced.
Ideally, insulating layers are both thin and warm(opens in new tab) to effectively trap heat while preserving mobility, and mountaineering gear with those specifications has not always been around(opens in new tab). Since the turn of the century(opens in new tab), however, aerogels have helped make these specifications possible.
Aerogels in thermal clothing
Aerogel is an ultralight, solid material that is created by removing the liquid from a gel and replacing it with a gas(opens in new tab) (often ambient air), resulting in a porous nanostructure that is dry and rigid. The first research on aerogel was published in 1931 by chemist Samuel Kistler(opens in new tab), and it is often nicknamed “frozen smoke” or “solid cloud.”
Because aerogel is composed of 99.8% air by volume(opens in new tab), it has a low thermal conductivity. It also has an extremely low density, and these two properties combined make it an ideal choice for thermal insulation.
Until recent decades, it was notoriously difficult to handle aerogel due to its fragility. It was also expensive to manufacture. However, in 1993, the Kennedy Space Center awarded Aspen Systems Inc. a Small Business Innovation Research contract to create a flexible form of aerogel in the form of small blankets. By 1999, Aspen Systems had developed fiber-reinforced flexible aerogel blankets(opens in new tab), which led to commercial success.
A 2008 partnership(opens in new tab) between Element 21(opens in new tab) and the re-named Aspen Aerogels(opens in new tab) then created Zero-Loft, an amorphous silica gel-based material for insulated clothing. The name comes from a comparison to goose down, as Zero-Loft was designed to trap a person’s warmth without needing to produce “loft” (fluffiness or thickness to trap the warm air).
In 2010, Canadian mountaineer Jamie Clarke put the material to the test by wearing a Champion jacket dubbed the “Supersuit(opens in new tab)” containing Zero-Loft on part of an Everest summit. Although the Zero-Loft brand has now faded from the public, the core engineering premise behind aerogel in clothing remains prevalent today as cold weather climbing gear evolves. Recently, researchers have even looked to other avians besides geese for thermal insulation inspiration.
Bioinspired cellular aerogel fibers balance strength and flexibility in wearable insulation
One of the main problems with raw, monolithic aerogel is its rigidity: Under mechanical pressure, it shatters. To use aerogel in clothing, it must be blended into a fiber filling, formed inside a fiber matrix, bound or laminated to a coating, or sealed inside engineered structures within the garment.
Researchers from Tiangong University, Tianjin University of Science and Technology, and the Swiss Federal Technology Institute of Lausanne recently drew inspiration from penguin feathers(opens in new tab) to assemble aramid nanofibers (ANFs) into aerogel fibers. The goal was to improve the aerogel’s mechanical strength in soft clothing garments.
At a microscopic level, penguin feathers have a cellular core with a variety of pore sizes that are surrounded by thick, packed keratin. The keratin sheath yields high tensile strength while the unevenly distributed core allows for bending and compression. The ANFs were used to replicate these structures because of their stacking and hydrogen-bonding capabilities.
A wet-spinning process was used to assemble the ANFs into aerogel fibers through a series of covalent and noncovalent interactions. First, Kevlar fibers were deprotonated (had their protons removed) using an alkali mixture to form an ANF sol. This sol was injected with dibromo cross-linkers and passed through sequential coagulation baths in acid and water to form first a rigid shell and then cellular core, respectively.
The rigid outer shell demonstrated tensile strength of up to 74.6 MPa. In contrast, the pliable cellular core demonstrated softness, with bending and compression stresses of 33.8 and 39.8 kPa, respectively.
Overall, the study showed that weaving the penguin-inspired aerogel fibers into fabrics exhibited comparatively good insulation: A 0.9-mm-thick sweater woven with the fibers showed more thermal resistance compared to thicker items, such as a 2.5-mm knit sweater and a 15-mm down jacket. Although penguins may not be found on Mount Everest, their natural design might soon be.
“These results establish the cellular aerogel textile as a promising candidate for next-generation soft yet thermally protective clothing,” the researchers write. “Importantly, we envision that the cellular structure present in our aerogels and/or the molecular self-assembly approach governing its formation could be extrapolated to other material systems, including but not limited to elastomers, foams, metals, and concretes, thus overcoming the trade-off between high strength/rigidity and high softness/flexibility.”
The open-access paper, published in Nature Communications, is “Bio-inspired cellular aerogel fibers integrating high mechanical strength and softness for thermal insulation textiles(opens in new tab)” (DOI: https://doi.org/10.1038/s41467-026-71723-2).
Staying safe at greater heights
While these technological advancements in mountaineering insulation make the danger of hypothermia less likely, the improved gear can paradoxically make mountaineering less safe by reducing the logistical barriers to entry. Rather than an elite sport, more recreationists are attempting major peaks with the support of guided expedition companies and modern lightweight gear, leading to more total accidents(opens in new tab) even as the percentage death rate per climb has gone down.
To combat overcrowding and environmental degradation(opens in new tab), governments and land management agencies around the world have started implementing stricter regulations on the tourism climbing industry (see measures passed so far in 2026 here(opens in new tab) and here(opens in new tab)). With these measures in place, the world of mountaineering can remain safe even as some inexperienced climbers tend toward substituting technological tools for fundamental wilderness skills.
