Abstract
Surface Free Energy (SFE) has become a relevant design parameter to produce materials and devices with controlled wettability. The non-destructive measurement of SFE in nanopatterned super-hydrophobic hard surfaces is a challenge in both research and industry since in most cases time-consuming contact angle measurements are not feasible. In this work, we present a novel nanoindentation based method for the measurement of pull-off adhesive forces by carefully controlling environmental and instrumentation issues. The method is found to measure SFE over five orders of magnitude, covering hydrophilic to super-hydrophobic surfaces, and has been validated with contact angle measurements. Its limitations and shortcomings are critically discussed, with a specific focus on the experimental issues that could affect the reliability and reproducibility of the results. Finally, the potential applications of the newly developed methodology include fast non-destructive mapping of SFE over heterogeneous surfaces with spatially controlled wettability.Graphic abstract
Highlights
The ability to engineer and control surface free energy and wettability of functional materials is critical in industry, e.g. microelectronics, microsystem engineering, energy, photonics, tribology, tissue engineering and biomedical devices [1,2,3,4,5,6,7,8,9]
contact angle measurement (CAM) reveal a clear transition from a hydrophilic behavior for the flat reference samples to hydrophobic for the silanized sample, and to super-hydrophobic for the nano-patterned and silanized sample
In the case of the two reference flat samples, we found reasonable agreement between contact mechanics results and the contact angle measurements
Summary
The ability to engineer and control surface free energy and wettability of functional materials is critical in industry, e.g. microelectronics, microsystem engineering, energy, photonics, tribology, tissue engineering and biomedical devices [1,2,3,4,5,6,7,8,9]. Contact mechanics related problems, such as the uncontrolled adhesion of surfaces with complex shape and geometries, hugely affects the products and their applications in these sectors [10,11,12,13,14]. These problems arise from intertwined physicochemical properties of the contacting surfaces and the interfaces between them. The characterization of these surface and interface properties is important for reliability, reproducibility, and the ability to design a system with predictable performance. Many of the high-value products suffer from poor yield, low productivity, and unreliable end-use performance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
