(642i) Synthetic Brochosomes As Ultra-Antireflective, Super-Hydrophobic Biomimetic Materials in Multifunctional Films for Electrochromic Applications

Brochosomes [1-5] are bucky-ball shaped hollow nanostructures naturally produced by leafhoppers (Hemiptera; Cicadellidae). Brochosomes are superhydrophobic and are thought to possess ultra-anti-reflective properties. The physicochemical origins and biological purposes of these properties are not fully understood. We studied the structure-dependent optical [1] and hydrophobic properties of brochosomes found in different leafhopper species. Light-matter interactions in brochosomes are rendered tunable via the geometry of the brochosomes, hollow pits, order and disorder in assemblies, and inter brochosomal packing. Furthermore, the reflective and absorption properties are affected through light polarization, excitation energy of incident photons, and the incident direction of incident radiation. We further study the chemical properties of these protein-based composition in brochosomes and perform electrostatic force and nano-infrared measurements to study the coupling of these structures with applied electromagnetic signals. We construct artificial films of synthetic brochosome inspired structures as a tunable thermochromic material. Finally, we study the structure-optical property relationship in beetles (Coleoptera; Carabidae, Scarabaeidae, and Staphylinidae) to compare the underlying mechanism with leafhoppers, in attempt to better understand brochosome function.

References: [1] Banerjee, P., Burks, G. R., Bialik, S. B., Nassr, M., Bello, E., Alleyne, M., Freeman, B.D., Barrick, J.E., Schroeder, C.M., and Milliron, D.J. Structure derived anti-reflectivity at the nanoscale in leafhopper brochosomes, in preparation.

[2] Yang, S. et al. Ultra-antireflective synthetic brochosomes. Nat. Commun. 8, 1285 (2017).

[3] Rakitov, R. et. al. Brochosomes protect leafhoppers (Insecta, Hemiptera, Cicadellidae) from sticky exudates. J. R. Soc. Interface 10, (2013).

[4] Christ, A. et al. Controlling the Fano interference in a plasmonic lattice. Phys. Rev. B 76, 201405 (2007).

[5] Rybin, M. V., et. al. Switching from Visibility to Invisibility via Fano Resonances: Theory and Experiment. Sci. Rep. 5, 8774 (2015).