EMFi-New electret material for sensors and actuators

ElectroMechanical Film (EMFi) is a new electret material with a cellular structure. EMFi's advantage over other solid polymer electrets is based on its flexibility due to the voided internal structure combined with strong permanent charge, which makes EMFi very sensitive to dynamic forces exerted normal to its surface. The base material is low-priced polypropylene (PP). Structure, operation and characterisation of the EMFi material is described. EMFi, which can be applied in various sensors, switches, loudspeakers and special transducers, is patented world wide.