Periodic Reporting for period 1 - SusArt (Sustainable Artificial Iridocytes for Designed Visual Appearance)
Reporting period: 2023-08-01 to 2025-07-31
Color is a fundamental part of human life, from art and culture to consumer products such as packaging, cosmetics, and textiles. Today, most commercial pigments and colorants are produced from petroleum-based chemicals and heavy metals. These materials are often non-biodegradable, generate waste during production, and contribute to environmental pollution, including microplastic accumulation. At the same time, there is a growing societal and industrial demand for sustainable alternatives that combine functionality with environmental responsibility.
Nature offers a powerful inspiration for designing new colorants. Many living organisms, from butterflies to fish, create vibrant, iridescent colors not through chemical pigments but through structural coloration—the interaction of light with periodic nanoscale structures. Mimicking these natural systems provides a pathway to sustainable colors with reduced environmental impact.
By merging polymer chemistry, self-assembly, and bio-inspiration, the SusArt project (Sustainable Artificial Iridocytes for Designed Visual Appearance) was designed to explore this pathway. The project’s main objective was to create artificial iridocytes (light-reflecting cells found in fish and cephalopods) using biodegradable bottlebrush block copolymers (BBCPs). By controlling the self-assembly of these polymers into ordered nanostructures, the project aimed to develop sustainable, tunable photonic materials that can replace traditional pigments. Beyond coloration, these materials hold potential for adaptive coatings and smart optical devices.
Nature offers a powerful inspiration for designing new colorants. Many living organisms, from butterflies to fish, create vibrant, iridescent colors not through chemical pigments but through structural coloration—the interaction of light with periodic nanoscale structures. Mimicking these natural systems provides a pathway to sustainable colors with reduced environmental impact.
By merging polymer chemistry, self-assembly, and bio-inspiration, the SusArt project (Sustainable Artificial Iridocytes for Designed Visual Appearance) was designed to explore this pathway. The project’s main objective was to create artificial iridocytes (light-reflecting cells found in fish and cephalopods) using biodegradable bottlebrush block copolymers (BBCPs). By controlling the self-assembly of these polymers into ordered nanostructures, the project aimed to develop sustainable, tunable photonic materials that can replace traditional pigments. Beyond coloration, these materials hold potential for adaptive coatings and smart optical devices.
During the SusArt fellowship, the research focused on the design, synthesis, and self-assembly of biodegradable bottlebrush block copolymers (BBCPs) to generate bio-inspired photonic materials.
1. Polymer synthesis and design
- Several series of sustainable BBCPs were successfully synthesized with controlled backbone length and sidechain density.
- Characterization by NMR, GPC, DSC, and TGA confirmed structural precision, thermal stability, and narrow dispersity, providing the foundation for reproducible self-assembly.
2. Self-assembly and structural coloration
- BBCPs were confined in emulsion droplets using microfluidic techniques, which induced ordered lamellar morphologies resembling natural iridocytes.
- Optical microscopy and UV-vis spectroscopy confirmed structural color generation spanning blue to red, demonstrating tunable coloration through molecular design and confinement.
- SAXS, SEM, and TEM analysis revealed hierarchical nanostructures and correlated nanoscale order with macroscopic color.
3. Stimuli-responsive nanonetworks
- Proof-of-concept materials were created where applied strain modified lamellar spacing and produced reversible color shifts.
- Preliminary incorporation of strain induced optical response.
- These adaptive systems represent an important step toward smart, responsive photonic coatings.
4. Integration of characterization methods
- An integrated pipeline was established combining scattering (SAXS), electron microscopy, spectroscopy, and custom-built optical setups.
- This multi-modal approach enabled detailed structure–property correlations, advancing both fundamental understanding and methodology in polymer photonics.
5. Training and laboratory establishment
- A dedicated polymer synthesis laboratory was set up at MPIKG, equipped with advanced polymer and optical characterization tools.
- The fellow supervised students and initiated collaborations with Fraunhofer IAP and Penn State, strengthening knowledge transfer and capacity building.
1. Polymer synthesis and design
- Several series of sustainable BBCPs were successfully synthesized with controlled backbone length and sidechain density.
- Characterization by NMR, GPC, DSC, and TGA confirmed structural precision, thermal stability, and narrow dispersity, providing the foundation for reproducible self-assembly.
2. Self-assembly and structural coloration
- BBCPs were confined in emulsion droplets using microfluidic techniques, which induced ordered lamellar morphologies resembling natural iridocytes.
- Optical microscopy and UV-vis spectroscopy confirmed structural color generation spanning blue to red, demonstrating tunable coloration through molecular design and confinement.
- SAXS, SEM, and TEM analysis revealed hierarchical nanostructures and correlated nanoscale order with macroscopic color.
3. Stimuli-responsive nanonetworks
- Proof-of-concept materials were created where applied strain modified lamellar spacing and produced reversible color shifts.
- Preliminary incorporation of strain induced optical response.
- These adaptive systems represent an important step toward smart, responsive photonic coatings.
4. Integration of characterization methods
- An integrated pipeline was established combining scattering (SAXS), electron microscopy, spectroscopy, and custom-built optical setups.
- This multi-modal approach enabled detailed structure–property correlations, advancing both fundamental understanding and methodology in polymer photonics.
5. Training and laboratory establishment
- A dedicated polymer synthesis laboratory was set up at MPIKG, equipped with advanced polymer and optical characterization tools.
- The fellow supervised students and initiated collaborations with Fraunhofer IAP and Penn State, strengthening knowledge transfer and capacity building.
The project delivered several outcomes that advance the field:
- Sustainable pigments: Demonstrated, for the first time, that biodegradable BBCPs can be used to generate tunable structural colors across the visible spectrum, offering a sustainable alternative to conventional pigments and glitters.
- Artificial iridocytes: Established a new method to replicate the functionality of biological iridocytes in synthetic, eco-friendly materials, bridging bio-inspiration with polymer science.
- Adaptive photonics: Opened a new direction by developing mechano-responsive nanonetworks, moving beyond static coloration toward dynamic, stimuli-responsive systems.
- Methodological innovation: Created an integrated optical characterization framework applicable to broader polymer and nanophotonic research.
Potential impacts and next steps
- Further research: Scaling up microfluidic confinement methods and improving reproducibility are necessary for industrial uptake.
- Commercialization: Sustainable pigments and coatings from BBCPs are highly relevant for packaging, textiles, and cosmetics, but require demonstration at pilot scale and engagement with industrial partners.
- IP and exploitation: While no IP was filed during the fellowship, future patent applications are possible once reproducibility and scalability are established.
- European positioning: By advancing bio-inspired photonics, the project strengthens Europe’s role in developing sustainable material technologies in alignment with the European Green Deal.
In conclusion, SusArt advanced polymer science beyond the state of the art, created new pathways for sustainable coloration, and laid the foundation for adaptive photonic materials with potential societal and industrial impact.
- Sustainable pigments: Demonstrated, for the first time, that biodegradable BBCPs can be used to generate tunable structural colors across the visible spectrum, offering a sustainable alternative to conventional pigments and glitters.
- Artificial iridocytes: Established a new method to replicate the functionality of biological iridocytes in synthetic, eco-friendly materials, bridging bio-inspiration with polymer science.
- Adaptive photonics: Opened a new direction by developing mechano-responsive nanonetworks, moving beyond static coloration toward dynamic, stimuli-responsive systems.
- Methodological innovation: Created an integrated optical characterization framework applicable to broader polymer and nanophotonic research.
Potential impacts and next steps
- Further research: Scaling up microfluidic confinement methods and improving reproducibility are necessary for industrial uptake.
- Commercialization: Sustainable pigments and coatings from BBCPs are highly relevant for packaging, textiles, and cosmetics, but require demonstration at pilot scale and engagement with industrial partners.
- IP and exploitation: While no IP was filed during the fellowship, future patent applications are possible once reproducibility and scalability are established.
- European positioning: By advancing bio-inspired photonics, the project strengthens Europe’s role in developing sustainable material technologies in alignment with the European Green Deal.
In conclusion, SusArt advanced polymer science beyond the state of the art, created new pathways for sustainable coloration, and laid the foundation for adaptive photonic materials with potential societal and industrial impact.