Recyclable biobased injection molded elastomer spring sole for sustainable footwear
A sustainable injection molded elastomer spring sole that replaces conventional EVA cushioning with a lightweight, biobased, 100% recyclable and biodegradable alternative. Validated for joint impact reduction, comfort across extreme temperatures, and durability over 1000 miles, with proven manufacturing processes and an established supply partnership.
Overview
This solution is a sustainable elastomer spring unit sole designed to replace the industry-standard ethylene vinyl acetate (EVA) midsole used in most footwear. Developed through years of biomechanics research at the University of Virginia and commercialized by OESH Shoes, the sole delivers measurable improvements in comfort, joint protection, and environmental sustainability. It is lightweight, low-density, biobased, 100% recyclable, and biodegradable, addressing growing consumer and regulatory demand for circular footwear materials.
Key benefits include:
- Reduced impact on lower extremity joints, objectively validated using 3D motion and force plate gait analysis
- Consistent comfort and performance across a wide temperature range, from -40°C to 100°C
- Maintained shape, rebound, traction, and insulative r-value through a minimum of 1000 miles of use
- Full recyclability and biodegradability, eliminating end-of-life waste associated with EVA
Technical specifications
The sole is produced using a proprietary injection molding process supported by custom-designed tooling and molds, enabling scalable manufacturing. Two complementary production methods have been developed and market-tested:
- Injection molding of a lightweight thermoplastic polyurethane (TPU) unit sole with a durable outsole region and a springy midsole region
- 3D printing using a proprietary pellet-based process, supported by National Science Foundation grants, that is fast, efficient, and requires minimal post-processing
Material development is conducted in partnership with Huntsman, a leading specialty chemicals supplier, with demonstrated 100% recyclability of the sole material. The sole design is informed by biomechanical research evaluating footwear attributes such as cushioning, heel elevation, and motion control, resulting in a spring structure that reduces joint loading during gait.
Technology readiness level
The technology has been validated in the marketplace through OESH Shoes' existing TPU unit sole products, which incorporate both injection molded and 3D printed variants. Recyclability has been independently demonstrated with material supplier Huntsman. The next phase of development involves iteratively refining specialized tooling and molds for an infinitely scalable injection molding process, followed by mechanical testing in isolation and biomechanical testing combined with shoe uppers. Validation endpoints include perceived comfort across temperature extremes, joint impact reduction, physical property retention, and durability over 1000 miles. The planned development timeline is approximately one year, with an ongoing partnership with Huntsman for material supply and a target of licensing, co-branding, or acquisition partnerships with major footwear brands.
About JKM Technologies, LLC DBA as OESH Shoes
OESH Shoes, a subsidiary of JKM Technologies, LLC, is a Charlottesville, Virginia-based company founded in 2011 by physician, scientist, and engineer Dr. Casey Kerrigan. The company designs footwear based on extensive biomechanical and gait research, prioritizing long-term health by avoiding features like heel elevation and narrow toe boxes that can negatively impact body alignment. OESH has developed and implemented a unique, patent-pending pellet-based 3D printing process for manufacturing its shoes. This technology, supported by National Science Foundation grant funding, allows for large-scale production while minimizing the use of toxic adhesives and noxious materials typical in traditional footwear manufacturing.
OESH products are designed to enhance natural movement and promote body health, providing a functional alternative for consumers, including those managing conditions such as plantar fasciitis. The company produces a variety of styles, such as sandals, that incorporate its signature bouncy engineered elastomer sole. By integrating scientific research with advanced manufacturing techniques, OESH aims to improve physical wellness and comfort for women and, more recently, men. The company maintains an active presence in the industry, directly selling its footwear online and engaging in ongoing product innovation.
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