Modelling the sensor and actuator operations of the ElectroMechanical Film EMFi

TLDR

The ElectroMechanical Film (EMFi) is a thin, cellular, biaxially oriented polypropylene film with metal electrodes, and prior elementary models have used a single air gap structure to describe its sensor and actuator behavior. This work introduces a model based on a multiple air gap structure for EMFi. The model, which reduces to a single air gap representation, is grounded in charge layers at the polypropylene/air interfaces and on the film surfaces. The model was evaluated and shown to agree with experimental results.

Abstract

The ElectroMechanical Film (EMFi) is a thin, cellular, biaxially oriented polypropylene film coated with metal electrodes. Elementary models with one air gap structure have been previously proposed to describe the EMFi's operation as a sensor and as an actuator. In this work a model based on a multiple air gap structure is presented and shown to reduce into a model with one air gap. The models are based on charge layers on the polypropylene/air interfaces and on the film's surfaces. The models are evaluated with some experimental results.