Nano-Scale Physics of Icephobicity and Path Toward Durable Icephobic Surfaces

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Anti-icing surfaces play a critical role in human daily lives in cold climates by impacting a broad range of systems including infrastructure, transportation networks, and power generation systems. Icing in electricity transmission systems can lead to collapse of poles and towers and rupture of conductors. Icing in aircrafts results in increased drag and may lead to loss of lift force and potential catastrophic events. Icing in energy systems significantly drops the heat transfer rate leading to inefficient operation of these systems. According to the Lawrence Berkeley National Laboratory, ice storms account for 10% of power transmission outages in the United States. The financial loss for industries is estimated at $3-5 billion annually. In addition to financial losses, around 3 million people in the US suffer from power losses caused by ice storms every winter. Despite the vital role in society, the development of high-performance anti-icing surfaces for such demanding applications remains elusive. This research will involve experiments and theory to reveal the role of length scale, geometry, and interfacial curvature on ice formation, and will develop new tools to address icing.Non-wetting, liquid-infused and hydrated surfaces have inspired routes for development of anti-icing surfaces. However, high freezing temperature, high ice adhesion strength (~50-100 kPa) and subsequent ice accretion, low mechanical durability, and high production cost have restricted their practical applications. The goal of this research program is to elucidate the underlying nano-scale physics of ice formation and adhesion on surfaces which involves studies of thermodynamics, heat transfer and mechanics of solid-ice interfaces. These physics provide fundamental routes for suppression of ice formation and minimization of ice adhesion on surfaces. We propose to break the limit of icephobicity at the nano-scale. Through studies of ice nucleation and growth at the nano-scale using Environmental Scanning Electron Microscopy and confined nano-channels, we will explore the icephobicity limits. A new predictive mathematical model on ice adhesion is proposed that provides fundamental routes to achieve extremely low ice adhesion along with high durability. Investigators will examine this predictive model and subsequently develop and characterize a new class of icephobic materials called 3D nano-viscoelastic materials. These anti-icing materials will be examined through various icephobicity and durability metrics. The educational tasks in this research program will provide a platform to discover the talents of students from underrepresented groups and to equip them with micro/nano engineering skills required for future multidisciplinary work environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.