Interfacial Strategies for Smart Slippery Surfaces

McHale, Glen, Ledesma Aguilar, Rodrigo and Wells, Gary (2020) Interfacial Strategies for Smart Slippery Surfaces. Journal of Bionic Engineering, 17 (4). pp. 633-643. ISSN 1672-6529

Preview	Text McHale2020_Article_InterfacialStrategiesForSmartS.pdf - Published Version Available under License Creative Commons Attribution 4.0. Download (1MB) | Preview
Preview	Text 2020_J_Bionic_Engineering_Accepted_Version.pdf - Accepted Version Download (588kB) | Preview

Abstract

The problem of contact line pinning on surfaces is pervasive and contributes to problems from ring stains to ice formation. Here we provide a single conceptual framework for interfacial strategies encompassing five strategies for modifying the solid-liquid interface to remove pinning and increase droplet mobility. Three biomimetic strategies are included, i) reducing the liquid-solid interfacial area inspired by the Lotus effect, ii) converting the liquid-solid contact to a solid-solid contact by the formation of a liquid marble inspired by how galling aphids remove honeydew, and iii) converting the liquid-solid interface to a liquid-lubricant contact by the use of an lubricant impregnated surface inspired by the Nepenthes Pitcher plant. Two further strategies are, iv) converting the liquid-solid contact to a liquid-vapor contact by using the Leidenfrost effect, and v) converting the contact to a liquid-liquid like contact using slippery omniphobic covalent attachment of a liquid-like coating (SOCAL). Using these approaches, we explain how surfaces can be designed to have smart functionality whilst retaining the mobility of contact lines and droplets. Furthermore, we show how droplets can evaporate at constant contact angle, be positioned using a Cheerios effect, transported by boundary reconfiguration in an energy invariant manner, and drive the rotation of solid components in a Leidenfrost heat engine. Our conceptual framework enables the rationale design of surfaces which are slippery to liquids and is relevant to a diverse range of applications.

Actions (login required)

View Item

Downloads