Analytical modeling and decoupling of humidity effects in nanomechanical sensing based on sorption kinetics and viscoelastic stress relaxation.

Nanomechanical sensors have gained significant attention as powerful tools for detecting target analytes; however, their signals are often influenced by environmental humidity. In static mode operation, the sensing signals of nanomechanical sensors are obtained by a concentration-dependent sorption-induced mechanical strain/stress. In this study, we derive an analytical model to describe the response of viscoelastic material-coated nanomechanical sensors by incorporating humidity effects based on sorption kinetics and viscoelastic stress relaxation of receptor materials. This model is capable of reproducing the dynamic responses observed in the experiments under varying humidity conditions. Moreover, it allows for the subtraction of humidity effects, facilitating the precise isolation of analyte-specific signals. These results provide a theoretical framework for decoupling environmental background factors, such as humidity effects, in nanomechanical sensors.