Californian 3D printing materials producer Siraya Tech has announced the launch of Roamr, a new materials sub-brand for wearable products.
The first product under the Roamr name is a thermoplastic polyurethane material called TPU Air HR, developed for 3D printed footwear. It enters a part of the market that has long been boxed in by a familiar tradeoff.
Typically, designers end up choosing between standard TPU that offers durability but relatively low rebound and PEBA-based elastomers that deliver higher energy return at the cost of rigidity. The California-based producer says TPU Air HR is formulated to sit between these two options by combining softness with a higher level of rebound.
Narrowing the rebound-softness tradeoff
In practice, the performance of 3D printed footwear has been constrained primarily by the mechanical behavior of printable elastomers under repeated load rather than by geometry or printer capability.
While AM enables complex lattice structures and custom geometries, the usable range of midsole and structural components has remained limited by how materials trade off energy return, softness, and durability. As a result, many designs continue to depend more on material compromise than on structural optimization.
Techniques such as foaming and process-based hardness tuning adjust density and stiffness without changing the material itself. This shifts where a material sits in the tradeoff space and enables different combinations of weight, rebound, and how soft or firm it feels in printed parts.
Against that background, TPU Air HR is reported to achieve a rebound rate of between 48% and 50%, which Siraya Tech says is higher than standard TPU. The company says this is intended to reduce the soft, collapsing behavior seen in some printed soles while increasing energy return during use.
The filament is designed to support active foaming during printing, a process that can reduce part weight by up to 50% for the 80A version of the material and up to 57% for the 85A version, resulting in a lower-density internal structure.
By adjusting printing temperature, hardness can be tuned between 64A and 85A, allowing different hardness zones within a single part while retaining TPU’s typical flexibility rather than the higher stiffness associated with nylon. After foaming, the company says the surface finish differs from standard, non-foamed TPU prints and appears matte.
The initial Roamr lineup splits into two versions of the material, one aimed at midsoles and liners where higher damping is required and the other at outsoles and structural upper components. With that focus, the 80A variant will be available in black and beige, while the 85A variant will be available in black.
Siraya Tech has also listed compatibility with the Snapmaker U1 3D printer, Bambu Lab’s A1, P1S, and X1C systems, and that the material is suitable for high-speed and larger-scale 3D printing.
TPU Air HR is currently available for purchase in the United States through Amazon, with global shipping expected to follow.
The limits of printed footwear cushioning
The rebound vs. softness constraint is visible in the most established commercial examples of 3D printed footwear cushioning. Adidas and Carbon’s Futurecraft 4D program, which produced multiple shoe models since its debut in 2017, has shown that complex elastomer lattices can be manufactured at scale.
In those shoes, comfort and impact response come from a combination of lattice structure and a dedicated elastomer system, rather than from geometry alone, reflecting a broader dependence on material behavior in printed footwear.
At the more utilitarian end of the market, TPU lattice midsoles are also being produced at industrial scale. In China, AM company Z-Sharp 3D Technology built production capacity for up to 100,000 pairs per year of SLS-printed TPU midsoles for sports footwear, using lattice structures to reduce weight and improve comfort and breathability.
These parts are designed around durability and cushioning, placing them firmly on the softer and resilient side of the same rebound vs. softness tradeoff.
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Featured image shows a concept illustration of energy return in a 3D printed shoe using Roamr TPU Air HR. Photo via Siraya Tech.
