Do hierarchical mechanisms of superhydrophobicity lead to self-organized criticality?

Bio-inspired superhydrophobic surfaces can be used to reduce adhesion between micro/nanoelectromechanical systems (MEMS/NEMS) components. Surface roughness is crucial for superhydrophobicity; however, complicated mechanisms of wetting, contact angle hysteresis and regime transition require new approaches to the concept of surface roughness, such as hierarchical roughness. We suggest that hierarchical organization of dissipation mechanisms is related to hierarchical roughness and may lead to self-organized criticality. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.