Entropy of resilience: Formulism and validation using strained-induced surface wettability study on thin film alloys

To circumvent the lack of interfacial tension data, we introduced a new material thermodynamics property termed as entropy of resilience SR to promote the application of Young’s equation. Derived from Helmholtz free energy analysis, this property relates to a specimen’s reduction in entropy and heat formation process. Moreover, we demonstrate a non-linear entropy-strain relationship, and proposed entropy change can be characterized by tensile tests and water contact angle measurements. Hence, water contact angle change is established as a second-degree polynomial function of strain, validated by surface wetting measurement of intrinsically strained thin film NiTi. Accordingly, a ∼60° increase in water contact angle can be interpreted as an entropy reduction of 38.61 Jkg−1K−1. This newly defined concept of entropy of resilience corresponds to a new paradigm shift wherein entropy is regarded as the predominate thermodynamic driver of surface wetting.