Fractal nematic colloids

Hashemi, S. M. (author), Jagodič, Uroš (author), Mozaffari, M. R. (author), Ejtehadi, M. R. (author), Muševič, Igor (author), Ravnik, Miha (author)

Fractals are remarkable examples of self-similarity where a structure or dynamic pattern is repeated over multiple spatial or time scales. However, little is known about how fractal stimuli such as fractal surfaces interact with their local environment if it exhibits order. Here we show geometry-induced formation of fractal defect states in Koch nematic colloids, exhibiting fractal self-similarity better than 90% over three orders of magnitude in the length scales, from micrometers to nanometres. We produce polymer Koch-shaped hollow colloidal prisms of three successive fractal iterations by direct laser writing, and characterize their coupling with the nematic by polarization microscopy and numerical modelling. Explicit generation of topological defect pairs is found, with the number of defects following exponential-law dependence and reaching few 100 already at fractal iteration four. This work demonstrates a route for generation of fractal topological defect states in responsive soft matter.

• Language: English
• Keywords: soft matter physics, colloidal particles, nematics, fractals, topology
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Publisher: Nature Publishing Group
• Year: 2017
• Number of pages: Str. 12106-1-14026-9
• Numbering: Vol. 8
• PID: 20.500.12556/RUL-99797
• UDC: 53
• ISSN on article: 2041-1723
• DOI: 10.1038/ncomms14026
• COBISS.SI-ID: 30202663
• Publication date in RUL: 16.02.2018

Record is a part of a journal

• Title: Nature communications
• Shortened title: Nat. commun.
• Publisher: Springer Nature
• ISSN: 2041-1723
• COBISS.SI-ID: 2315876

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 16.02.2018

Projects

• Funder: EC - European Commission
• Funding programme: FP7
• Project number: 304040
• Name: Channelfree liquid crystal microfluidics
• Acronym: FREEFLUID