Towards Scalephobicity: Soft Surface Microengineering for Microfoulant Repellency

Particulate and crystallization fouling, ubiquitous in nature and technology, pose significant challenges to the efficiency of water treatment, desalination, and energy conversion processes. Current solutions rely heavily on active methods like antiscalant additives or mechanical removal, necessitating a shift towards sustainable, passive strategies, such as surfaces with inherent self-cleaning or anti-fouling properties. Existing research has focused on modifying the surface energy and texture of rigid materials for anti-fouling surfaces, overlooking the potential of compliant materials with intrinsic foulant-repellent properties. The intricate interplay of substrate compliance, composition, and surface texture in an aqueous environment and their impact on microfoulant adhesion at the microscale remain largely unexplored. In this study, we employ a micro-scanning fluid dynamic gauge (µ-sFDG) setup to conduct in-situ shear removal experiments for calcium carbonate and polystyrene micro-foulants on compliant anti-fouling surfaces. Guided by adhesion and fluid mechanics theory, and through rational micro-engineering of compliant materials, our findings reveal counterintuitive results: compliant materials surpass their rigid counterparts in anti-fouling performance. This research provides promising insights for the design of compliant interfacial materials capable of achieving high anti-fouling efficacy against particulate and crystallization fouling across various industrial applications including water and energy conversion systems.