Electromechanical Film (EMFi) is a thin, flexible film that can function as a sensor or actuator. It is composed of a charged polymer coated with two conductive layers, making it an electret. It was first made by Finnish inventor Kari Kirjavainen. EMFi's voided internal structure and high resistivity allows it to hold a high electric charge and makes the film very sensitive to force. Through either measuring the film's internal electric field generated from an electric charge, or changes in the film's thickness in the when an electric voltage is applied, EMFi can function either as a sensor, or an actuator. This gives the film applications in different fields of technology, including, but not limited to, microphones, loudspeaker panels, keyboards, and physiological sensors. Other than bein