Journal Article

Switchable Static and Dynamic Self-Assembly of Magnetic Droplets on Superhydrophobic Surfaces

Timonen, Jaakko V. I., Latikka, Mika, Ras, Robin H. A., Ikkala, Olli, Leibler, Ludwik

2013

Overview

Self-assembly is a process in which interacting bodies are autonomously driven into ordered structures. Static structures such as crystals often form through simple energy minimization, whereas dynamic ones require continuous energy input to grow and sustain. Dynamic systems are ubiquitous in nature and biology but have proven challenging to understand and engineer. Here, we bridge the gap from static to dynamic self-assembly by introducing a model system based on ferrofluid droplets on superhydrophobic surfaces. The droplets self-assemble under a static external magnetic field into simple patterns that can be switched to complicated dynamic dissipative structures by applying a time-varying magnetic field. The transition between the static and dynamic patterns involves kinetic trapping and shows complexity that can be directly visualized.

• Publisher: American Association for the Advancement of Science,The American Association for the Advancement of Science,American Association for the Advancement of Science (AAAS)
• Subject: Assembly / composite polymers / Condensed Matter / Condensed matter: electronic structure, electrical, magnetic, and optical properties / Copolymers / Cross-disciplinary physics: materials science; rheology / Crystals / Drop size distribution / Droplets / Dynamical systems / Dynamics / Electronics / Energy / Energy sources / Exact sciences and technology / Ferrofluids / Film criticism / Hydrophobic surfaces / hydrophobicity / Kinetics / Magnetic field strength / Magnetic fields / Magnetic liquids / Magnetic properties and materials / Magnetism / Magnets / Materials science / Methods of nanofabrication / Movies / Physics / Segregations / Self assembly / Soft Condensed Matter / Studies of specific magnetic materials