Biocomposite Climbing Holds

︎ Creators: Uma Freitag and Josh White      
︎ Supervisor: Peter Yeadon


For this project, we set out to create a structural biomaterial that could act as a reliable support while also being biodegradable. We explored several early recipes, including agar, rice husk composites, and varous concrete-like biomaterials made with wood ash, cornstarch, and seashell. Ultimately, we returned to a sample that had previously been made. That earlier composite was extremely dense, rock hard, and easy to sand and shape, but it relied on spackle and wood glue, which did not align with our goal of creating a fully sustainable material. We rethought the composition of that sample and began refining new recipes that replaced the synthetic binders with gelatin.

Our final recipe blended dried leaves, sawdust, newspaper fibers, water, dye, and gelatin. The mix of different particle sizes created a natural internal structure similar to concrete, where larger fragments provide bulk and smaller fibers fill the gaps. To achieve stronger parts, we created pressure molds that allowed us to compress the material as it cured, resulting in higher density and greater load bearing capacity. Along the way, we experimented with natural dyes such as indigo, cochineal, logwood, and charcoal, but ultimately chose synthetic dyes for their more saturated colors, which helped our samples visually align with real bouldering walls for presentation purposes.

Through our shared love for bouldering, a ropeless form of rockclimbing, we speculated on whether we could create climbing holds out of our biomaterial. We digitally modeled and printed three-part molds, cast our first samples, and dried them in a dehydrator before letting them finish curing in open air. After bolting them to a wall, we revealed that a single hold could take at least 72 kg (160 lbs.) without breaking. This was when we realized our biocomposite was sturdy enough to support real climbing weight, which led us to pursue a full-scale climbing wall for our final project.

To bring the installation to life, we built a wooden frame to mount the holds and constructed a modular climbing section for the classroom. We created a range of mold designs to replicate common climbing hold types such as footholds, pinches, crimps, and jugs, demonstrating the versatility of the material. During our final presentation, we encouraged classmates and visitors to test the wall themselves, inviting people to trust the composite rather than fear the idea of a biodegradable material supporting their weight.

As climbing holds are primarily manufactured from polyurethane (PU) or polyester resin (PE), the installation became an interactive demonstration of a reliable and sustainable alternative that can be primarily made with waste materials.