Bioinspired superamphiphobic microreactor for efficient fabrication of cellulose nanocrystal photonic pigments

Bioinspired superamphiphobic microreactor mimics starfish tube feet for transport. • Superamphiphobic surface repels water, oil, and cellulose nanocrystal droplets (CA > 150°). • Magnetic response enables droplet transport at speeds up to 16 mm s −1 . • Continuous photonic pigment production achieved at 116.28 g m −2 d −1 . The practical application of cellulose nanocrystal photonic pigments is hindered by their time-consuming and discontinuous preparation processes. Inspired by the transport phenomenon and mechanism of starfish tube feet, a bioinspired superamphiphobic microreactor is fabricated massively via an industrial micro-extrusion compression molding technology for the efficient fabrication of photonic pigments. The microreactor, featuring a starfish tube feet-inspired micropillar, demonstrates exceptional superamphiphobicity, with cellulose nanocrystal suspension contact angle of 156.6 ± 2.2°. Furthermore, the incorporation of magnetic particles imparts the microreactor with a sensitive magnetic response. This enables the precise transport of cellulose nanocrystal droplets at high speeds of up to 16 mm s −1 . Remarkably, the microreactor maintains consistent performance over more than 100 cycles, demonstrating exceptional durability. Leveraging these attributes, the microreactor mimics the rhythmic motion of starfish tube feet to propel the cellulose nanocrystal droplets to designated locations for self-assembly into particles and subsequent collection. Then the dried particles can be efficiently transported and collected, achieving continuous production for the photonic pigments at a rate of 116.28 g m −2 d −1 . The proposed approach offers a robust strategy for the scalable manufacturing of photonic pigments and advancing their path to practical application. The bioinspired superamphiphobic microreactor with surface micropillars is fabricated via micro-extrusion compression molding. Under a moving magnetic field, these micropillars are actuated to directionally propel cellulose nanocrystals suspension droplets for self-assembly into photonic pigment particles. This process enables continuous production and collection, providing a novel strategy for industrial application of structural color materials. Download: Download high-res image (356KB) Download: Download full-size image