With recent advances in wood engineering, enthusiasm for minimizing the embodied carbon of construction has led to increased interest in mass timber. Growing demand for wood products has motivated the transformation of pulp mills to bioproducts mills—factories that make holistic use of trees for a variety of industries, including textiles and packaging. Today, the range of wood products and fabrication processes available is unprecedented, and thus invites increased scrutiny and creative experimentation by architects and designers.
A noteworthy example is the Future of Wood studio at the University of Arkansas Fay Jones School of Architecture and Design, directed this fall by associate professor Frank Jacobus. Supported in part by a U.S. Endowment for Forestry and Communities grant, the studio challenged fifth-year B.Arch. students to explore novel wood fabrication techniques for architecture and engineering using three- and five-axis CNC milling machines, 3D printing, and other technologies.
While wood-focused design-build investigations are common in academia, the Future of Wood uniquely focuses almost exclusively on fine wood particles as raw feedstock for new material constructions. By working with wood flour, sawdust, and various adhesives and fillers, the students effectively crafted their own engineered wood products—and then built architectural structures with them.
As may be expected, the process was messy, time-intensive, nonlinear, and unpredictable. Jacobus intentionally left the studio syllabus open-ended, writing that “a studio feedback loop will help us determine new ideas to explore and we will be consistently asking about the nature of the printed or milled formal constructs and how they might translate into a more comprehensive architecture.” Despite these qualities (or perhaps because of them), the students gained significant knowledge from the experience.
One line of material inquiry emerged with a focus on cast composites as students experimented with mixtures composed of wood flour, wood hardener, baking flour, epoxy resin, polyvinyl acetate glue, and water. A team formed around the challenge to create large cast modules with sufficient structural strength, physical integrity, and uniform appearance for use in constructing a small pavilion. At first, the students created mixes with 50% wood flour but later determined that they could increase the proportion to 80% with the incorporation of two-part epoxy resin—a combination that produced the most robust panels they tested. Next, the team developed a series of plywood molds with varied profiles and curvature to showcase the highly formable nature of the wood composite. During the casting process, the students incorporated chicken wire between layers of material to minimize cracking. While the original intent was to devise a mortise-and-tenon joint strategy to create a self-supporting structure, the team ultimately determined that the overall form was too complicated and the joints too tenuous for such an approach. Instead, they constructed an internal wood framework for additional structure.
Using a 3D Potterbot Scara, a printer devised for the additive manufacturing of ceramics, other students tested a variety of slurries to explore the possibilities of 3D printed wood. Initial mixtures included equal parts wood flour, baking flour, and PVA glue; additional experiments included wood filler, joint compound, epoxy resins, linseed oil, and tree sap rosin. After extensive testing resulting in an array of stratified objects, the team prioritized the fabrication of a skeletal “tile” made of intersecting lines of material. The final modules consisted of a maximum of 55% wood flour (higher quantities would dry out or clog the 3D printer), epoxy resin, PVA glue, baking flour, and water. Determining that the tiles could be draped over curved formwork to provide improved structural rigidity, the students designed a tripod-frame pavilion using the modules. The ambitious proposal involved developing robust inter-panel joints, which the students resolved using string and animal hide glue, as well as the provision of column “footings” made of plywood.
In both projects, Jacobus’ students accomplished significant feats of material experimentation and design. Not only did they develop workable mixtures for wood-based composites using unfamiliar tools, but they also devised compelling structures using their newly engineered materials. Both phases of the process involved substantial risks of failure: The students spent weeks creating material slurries without reliable outcomes, and built ambitious constructions while continually managing the challenges of imminent fracture and collapse.
Yet these risks resulted in significant rewards. The students gained tremendously from a crash course in materials science, rigorous and frequent interrogations of the concepts of beauty and craft, learning to work effectively in large groups, and—perhaps most importantly—the experience of developing a methodology to address unanswered questions, with uncertain outcomes.
Pedagogical benefits aside, how is Jacobus’ studio relevant to the future of wood? The arc of engineered wood composite technology does indicate ever greater levels of processing and testing, particularly given the carbon sequestering ability of wood. Ideally, such composites would eschew epoxy in favor of a nontoxic, bio-based adhesive, such that the materials could safely biodegrade at the end of their useful lives with more limited adverse environmental effects. Given the variety of high-performing engineered wood products available today, the wood flour-composite approach is particularly attractive as a way to utilize fabrication waste (e.g., sawdust) as well as incorporate other discarded biomaterials such as rice husks or degraded paper products. In the context of this future research trajectory, the primary material contribution of Jacobus’ studio is the demonstration that well-designed, robust structures can be crafted from the weakest and least desirable of feedstocks.
