Key points
- Agar bioplastic, tunable with bone glue/plasticisers: thin, translucent, low structural strength, mounted on birch frames.
- Phycocyanin = brilliant blue, UV-sensitive → best for indoor/temporary installations.
- Battery-LED lighting used to soft-enhance transparency under power constraints.
- Process is seasonal to avoid mould: summer casting, balcony cure, autumn delivery.
- Pipeline expands to shell-based bioconcrete and built projects that merge bio-construction with biodesign.
Full interview with Kathryn Larsen
1. In the #SeaweedSelfie wall, you combined birch with a seaweed bioplastic and phycocyanin pigment. Could you specify the advantages and limitations of the seaweed bioplastic in achieving both structural integrity and visual transparency?
The seaweed bioplastic is one I make myself from agar, and I can increase either the rigidity or tensile strength depending on what additives I use, bone glue for rigidity and plasticizers like honey or glycerol for flexibility. However, it's generally quite thin and lacks much structural integrity. My preferred formula has a bit of stretch so I can attach it to the wooden birch frame in a flat layer. I love experimenting with transparency: agar bioplastics have a natural cloudiness, while bone glue variations can exhibit a rainbow-like reflectivity.
2. The blue hue in your installation derives from phycocyanin, a pigment from blue‑green algae. How does this natural dye impact long-term colour stability and environmental performance compared to synthetic alternatives?
I only use phycocyanin for interior or temporary installations, as its color degrades under UV exposure. That said, it’s an incredibly brilliant blue - most people are shocked to learn it comes from algae! I used to source mine from a startup that had patented special growing conditions to enhance pigment concentration, but they’re no longer operating.
3. In designing Atarashii Arbejdsplads, you created sculptural, vibrant pools. How did material selection influence the fluid separation of functional zones while maintaining cohesion across the workspace?
As part of a competition entry for 3daysofdesign, we were limited to pre-existing Montana furniture modules and colours. William Qian and I treated these like Lego blocks to build sculptural towers in the Montana showroom. We aimed to demonstrate how furniture could spatially become a garden. We didn’t win, but received an honourable mention from colour designer Margrethe Odgaard.
4. Could you describe how the birch framework interacted with the seaweed microalgae paint in terms of adhesion, texture, and finish in the selfie installation?
I wanted to create a biobased alternative to stained glass using birch and algae-derived materials. The cutouts mimic floral patterns through biomimicry. Birch acted as the structural divider, while the phycocyanin paint - an adaptation of my bioplastic recipe - was made more watery. It behaved more like a stain, highlighting the natural wood grain and showing off the honest character of each material.
5. For the competition proposal, how did you evaluate emerging or atypical materials to maintain the Zen-inspired calm yet dynamic energy of the space?
We were restricted to using only Montana’s existing modules, so I couldn’t incorporate atypical or biobased materials. Unfortunately, the Danish design industry is still relatively new to such innovations.
6. The Seaweed Selfie demanded mobility and lighting sensitivity. What mechanical or optical properties of the bioplastic informed your choices for integrated LED lighting - especially with battery‑power constraints?
In this case, the bioplastic wasn’t the deciding factor-power access was. The setup had no direct power supply, so I opted for battery-powered LEDs. I positioned the lighting to gently enhance transparency without overexposing the selfie subjects. Too much backlight would have silhouetted them entirely.
7. Regarding ecological impact, how do you assess the lifecycle of your seaweed bioplastic, and how does it contrast with more conventional biomass materials?
Frankly, I don’t. As a small practitioner, I lack the capacity and funding for full lifecycle assessments. There’s little transparency in material production, and while I vet suppliers and work with trusted farmers, true traceability is rare unless governed by something like FDA-level regulations, which I only encounter in my pharmaceutical architecture work.
8. Can you elaborate on fabrication challenges unique to seaweed‑based materials, such as bending, curing, or surface finishing, and how you adapted traditional woodworking or craft techniques?
Mold is the biggest challenge with agar bioplastics. Some designers use dehydrators, but I simply tell clients that I only deliver in autumn, after summer casting and balcony drying. All my bioplastics for the #SeaweedSelfie wall dried in the hot sun on my balcony.
9. Given your experimentation with biomaterials and spatial narrative, which emerging material technologies (e.g., algae composites, mycelium structures, recycled laminates) are you most excited to integrate into future projects?
I recently spent three years developing a shell-based bioconcrete, which evolved into a fast-moving ocean restoration company. Now, I’m weaving those experiments into my Eskilstrup Kulturhus project, blending traditional biobased construction with contemporary biodesign in a permanent, built structure.
