Nature Communications has research from Cornell ornithologists and material engineers who created a new blacker-than-black dress that’s breathable and stretchable, because it’s made from natural fibers, using the light-absorbing properties seen in the feathers of the magnificent riflebird (Ptiloris magnificus):
Some animals express an extreme level of black color, called “ultrablack” with reflectance <0.5%. The various nano/microstructures that produce ultrablack have been studied and replicated synthetically. These synthetic ultrablack materials, however, use highly advanced and costly techniques, toxic substances, and lack the flexibility and biocompatibility that are often desired in real-world textile applications. Here we show that a conventional natural fabric can be transformed into an ultrablack one with a biocompatible dye and a surface modification to create nanofibrils. The ultrablack wool fabrics we report have an average total reflectance of 0.13% (λ = 400–700 nm) and represent the darkest fabrics currently reported. Unlike commercially available ultrablack fabrics, the ultrablack wool developed in this study remains breathable and conformable.
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Our two-step method includes one-pot polydopamine (PDA) dyeing of merino wool followed by plasma treatment. This study demonstrates the fabrication and validates the properties of ultrablack wool (UBW) through microscopic and spectrophotometric analyses, surface characterization, and optical simulations. We report wash-fastness, lightfastness, and mechanical durability, which confirm the real-world pertinency of UBW as a flexible, breathable, and wearable optical material.
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The magnificent riflebird (Ptiloris magnificus), a species of the bird of paradise family (Fig. 1a inset), has hierarchical barbules that curve up to form a densely packed tilted array (~30°) toward the distal tip of the feather (Fig. 1a)2. The presence of the intra-barbule grooves (~5–30 µm), with smaller cavities (<5 µm) along the barbule margins and their melanin-based internal nanostructures, results in the ultrablack coloration that is meant for display, rather than camouflage2. Inspired by this structure-induced darkness, the centerpiece of the dress in Fig. 1b portrays the contrast between the ultrablack wool (UBW) against the iridescent blue and commercially available black polyester blend (BPETB) fabrics.
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You can read more of the ultrablack wool data here, at Cornell’s library.