In the field of thermal insulation, aerogel has long been regarded as one of the solid materials with the lowest thermal conductivity. Often described as “solid smoke,” it has earned a reputation as a gold standard in high-performance thermal insulation.
However, aerogel has a major weakness: brittleness.
Its extremely high porosity contributes to exceptionally low thermal conductivity, but it also results in limited mechanical strength. Conventional aerogels can fracture under bending or pressure and present significant challenges in cutting, sewing, and other forms of processing.
For nearly a century, researchers and industry professionals have therefore sought an insulating material that could deliver thermal performance comparable to aerogel while remaining flexible and processable like a textile.
The development of Y-Warm has turned this possibility into reality.
I. What Is Y-Warm?
Y-Warm is a flexible thermal insulation material with a nanoscale closed-cell structure, developed by Y-Warm Technologies Co., Ltd.
Its development dates back to the launch of the project in 2013. In 2017, the company’s research team successfully developed what it describes as the world’s first flexible thermal insulation material featuring a nanoscale closed-cell structure. Technical validation was completed in 2019, followed by the start of commercial-scale production and market introduction in 2021.
From a materials science perspective, Y-Warm’s core breakthrough lies in its structure.
By employing a flexible polymer-based nano-closed-cell technology, the research team overcame the brittleness commonly associated with conventional gel-based materials. While maintaining extremely low thermal conductivity at a level comparable to aerogel, Y-Warm combines flexibility with practical processability, allowing the material to be sewn and machine-washed.
The R&D team summarizes these technical achievements as three “world firsts.”
First, it overcame brittleness, one of the long-standing mechanical limitations of nanoporous materials.
Second, it combined a closed-cell thermal insulation structure with both moisture permeability and quick-drying performance.
Third, it enabled low-thermal-conductivity insulation technology to be applied to cold-weather products such as winter apparel and footwear.
II. The Science Behind Y-Warm: How Does It Provide Thermal Insulation?
The thermal insulation performance of porous materials fundamentally derives from their ability to restrict heat transfer through gas trapped within their pores. This is one of the key principles that enables aerogels to achieve exceptionally low thermal conductivity.
Y-Warm is based on a similar fundamental principle, but its internal structure differs from that of aerogel.
Nano-CT and scanning electron microscopy (SEM) observations reveal a honeycomb-like internal structure. Nanoscale pore walls, approximately 20–280 nanometers thick, surround independent microscale closed cells with diameters of approximately 30–190 micrometers.
In porous thermal insulation materials, restricting the movement of gas within the pores plays an important role in reducing heat transfer. Y-Warm’s independent closed-cell structure limits internal gas movement and convection, thereby reducing heat transfer through the material.
At the same time, its thin pore walls help reduce material density and limit heat conduction through the solid matrix, contributing to high thermal insulation efficiency.
In addition, the micrometer-scale textured surface significantly increases the specific surface area. This contributes to high emissivity, giving the material additional thermal-radiation characteristics in the far-infrared range.
III. Performance Data
Thickness and Thermal Performance: Taking YW-01 as an example, the material is only 0.7 mm thick, yet when incorporated into a finished product, it can increase the perceived temperature by approximately 10°C under specified test conditions.
Operating Temperature Range: The material can be used across a temperature range of approximately −50°C to 150°C, while certain specifications have an upper operating temperature limit of 120°C.
Moisture Management and Quick-Drying Performance: Its water absorption capacity is approximately twice that of the standard reference fabric, while its evaporation rate is also approximately twice that of the reference sample. Even when fully saturated, the material can dry naturally at room temperature in approximately one hour.
Antibacterial Performance and Safety: Y-Warm incorporates an environmentally considerate antibacterial agent designed to maintain its effectiveness after repeated washing. The material has also passed testing for Substances of Very High Concern (SVHC) under the EU REACH framework.
Lightweight Construction: Y-Warm has an areal density of approximately 38–70 g/m². Even a 150 cm-wide roll can be easily handled by one person. Depending on the application and the material system being replaced, weight reductions of up to approximately 75% can be achieved.
Because Y-Warm is an ultrathin material with a microtextured surface, accurately determining its absolute thermal conductivity using standard measurement methods developed for conventional materials can be challenging. Measured values may therefore vary depending on the test method and conditions.
For this reason, Y-Warm’s low-thermal-conductivity and high-insulation characteristics are currently evaluated through a combination of multiple test methods and reference values rather than relying on a single measurement alone.
IV. Y-Warm vs. Aerogel: Alternative or Complement?
Describing Y-Warm as an “alternative to aerogel” requires consideration of the specific application. It should not be interpreted as meaning that Y-Warm comprehensively outperforms aerogel in every respect.
The two materials differ significantly in their composition, internal structure, mechanical properties, and target applications.
Conventional silica aerogels are composed primarily of inorganic silicon dioxide and feature a three-dimensional nanoporous structure. They provide exceptional thermal insulation performance but are generally brittle in their monolithic form. As a result, aerogel-based insulation technologies have been widely used in demanding applications where high thermal performance is critical, including aerospace, oil and gas pipelines, and battery thermal management.
Y-Warm, by contrast, is based on organic polymers and features nanoscale pore walls surrounding independent microscale closed cells. In addition to flexibility and resilience, it offers moisture permeability and quick-drying performance. These characteristics make it suitable for more than 20 low- and medium-temperature application fields, including apparel, tents, footwear, bedding, automotive interiors, and construction.
More precisely, in low- and medium-temperature applications where flexibility, moisture permeability, and processability are essential, Y-Warm can serve as a practical alternative to aerogel.
For high-temperature thermal insulation, however, aerogel continues to play an important and, in many applications, difficult-to-replace role.
What Y-Warm introduces is not simply another thermal insulation material, but a different approach to insulation: achieving high thermal efficiency with minimal thickness.
Conventional cold-weather insulation materials typically rely on thickness and loft to trap air and reduce heat loss. Y-Warm, by contrast, uses its fine closed-cell structure to restrict heat transfer without relying primarily on bulk.
This approach moves cold-weather protection beyond the conventional principle of “more thickness for more warmth,” providing a new insulation option that is lighter, thinner, and potentially more resource-efficient across a wide range of applications, from apparel and buildings to mobility.