Super-White Coating Inspired by Beetle Scales Offers Sustainable Alternative to Titanium Dioxide

Seprify, a Switzerland-based startup, has pioneered a novel super-white coating that draws inspiration from the microscopic structural properties of beetle scales. This innovative bio-inspired colorant is positioned as a sustainable and effective alternative to titanium dioxide (TiO2), a widely used white pigment that has faced increasing scrutiny. For decades, TiO2 has been the go-to for achieving brightness in a vast array of products, from paints and plastics to even food items like powdered donuts, owing to its efficacy and low cost. However, the European Union's ban on TiO2 as a food additive in 2022, citing potential health risks, has accelerated the search for viable replacements.

Seprify's approach, as explained by CEO and cofounder Lukas Schertel, tackles the inherent challenge of creating intense whiteness with minimal material and exceptionally thin films. "It’s not hard to make anything white, but making white using very little material and very thin films is the challenge that this beetle, over thousands of years of evolution, has solved very well," Schertel stated. The company's technology is a direct outgrowth of research conducted at the University of Fribourg and the University of Cambridge, where Schertel and his colleagues dedicated their efforts to understanding and replicating bio-inspired color mechanisms.

The resulting colorant is engineered as a "drop-in solution," meaning it can be seamlessly integrated into existing manufacturing workflows. It is a powder that can be utilized in the same formulations previously designed for titanium dioxide, simplifying adoption for manufacturers. The core of Seprify's innovation lies in its use of cellulose, described by Schertel as "the most abundant plant material we can find." This readily available and renewable resource is then meticulously shaped into complex microstructures that precisely mimic the way the beetle's exoskeleton scales scatter light to produce its striking white appearance.

The potential applications for this advanced coating are broad. Ingka Group, the parent company of furniture giant Ikea and an investor in Seprify, is actively exploring its use on furniture. This is particularly significant when considering the environmental impact. Conventional paints utilizing titanium dioxide often require mining and extensive processing, contributing to substantial emissions. Seprify's cellulose-based coating, in contrast, uses approximately half the amount of material to achieve an equivalent level of whiteness, thereby significantly shrinking its carbon footprint. Furthermore, the bio-based nature of the coating enhances product recyclability. For wood furniture, for instance, the cellulose coating ensures that the entire piece can be more easily recycled, aligning perfectly with Ikea's strategic commitment to circularity and sustainability.

Beyond furniture, the material also holds promise for the food industry, where it can serve as a safe and effective white colorant in various applications, offering a natural alternative to synthetic or mineral-based pigments. Seprify's development represents a significant advancement in material science, moving towards more sustainable, renewable, and environmentally conscious solutions.