Leakage at interfaces: A comprehensive study based on Persson contact mechanics theory

We present a comprehensive study that combines theory and experiments on gas leakage at rubber–glass interfaces in a prototype syringe system. Leakage measurements were conducted under controlled dry conditions and compared with predictions from a new approach that integrates finite element simulations, which neglect microscopic roughness and provide deterministic pressure profiles, with Persson contact mechanics and leakage theory. The latter incorporates the measured random surface roughness, characterized using stylus profilometry and atomic force microscopy, to determine local flow factors with high accuracy. The predicted leakage rates show good agreement with experimental results. Furthermore, sensitivity analyses reveal that small variations in elastic modulus and contact pressure can markedly influence leakage behavior, especially near the percolation threshold. This work establishes a generalized and experimentally validated framework for leakage prediction and provides practical guidance for the design and optimization of sealing systems in pharmaceutical and engineering applications.