Order and information in the patterns of spinning magnetic micro-disks at the air-water interface

Wang, Wendong; Gardi, Gaurav; Malgaretti, Paolo; Kishore, Vimal; Koens, Lyndon; Son, Donghoon; Gilbert, Hunter; Wu, Zongyuan; Harwani, Palak; Lauga, Eric; Holm, Christian; Sitti, Metin

Abstract

The application of the Shannon entropy to study the relationship between information and structures has yielded insights into molecular and material systems. However, the difficulty in directly observing and manipulating atoms and molecules hampers the ability of these systems to serve as model systems for further exploring the links between information and structures. Here, we use, as a model experimental system, hundreds of spinning magnetic micro-disks self-organizing at the air-water interface to generate various spatiotemporal patterns with varying degrees of order. Using the neighbor distance as the information-bearing variable, we demonstrate the links among information, structure, and interactions. We establish a direct link between information and structure without using explicit knowledge of interactions. Last, we show that the Shannon entropy by neighbor distances is a powerful observable in characterizing structural changes. Our findings are relevant for analyzing natural self-organizing systems and for designing collective robots.

Citation

Wang, W., Gardi, G., Malgaretti, P., Kishore, V., Koens, L., Son, D., …Sitti, M. (2022). Order and information in the patterns of spinning magnetic micro-disks at the air-water interface. Science Advances, 8(2), Article eabk0685. https://doi.org/10.1126/sciadv.abk0685

• Journal Article Type: Article
• Acceptance Date: Jan 14, 2022
• Online Publication Date: Jan 14, 2022
• Publication Date: 2022
• Deposit Date: Jan 25, 2022
• Publicly Available Date: Jan 28, 2022
• Journal: Science Advances
• Electronic ISSN: 2375-2548
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 8
• Issue: 2
• Article Number: eabk0685
• DOI: https://doi.org/10.1126/sciadv.abk0685
• Public URL: https://hull-repository.worktribe.com/output/3916656