A fast and accurate Langmuir-type polymer microtensiometer

A semi-flexible polymer microtensiometer for local surface pressure measurements of Langmuir monolayers is presented. The current device geometry and read-out method via image analysis result in a theoretical accuracy of ±0.02mN⋅m−1 for a dynamic range between 0 and 75mN⋅m−1. The tensiometer sensitivity and dynamic range are easily tunable as they are solely based on the tensiometer spring dimensions. Finite element simulations are used to determine the response time of 20ms for a subphase viscosity of 1mPa⋅s. A poroviscomechanical model of the sensor is composed and the subphase viscosity is shown to dominate the transient behavior. The tensiometer performance is verified in a Langmuir trough by applying rapid local surface pressure oscillations. A Wilhelmy plate is used as an independent measurement tool and the results of both techniques correlate well. [Display omitted] •Semi-flexible microtensiometer for Langmuir monolayer characterization•Tunable sensitivity and dynamic range by design•Fast response time and high accuracy, compared to state-of-the-art•Good correlation of results with independent reference measurements