Flexible and stretchable dielectrics

A brief tour d´horizon is given through recent research on flexible and stretchable dielectrics. Ultrathin dielectrics with low leakage currents and high breakdown strength are essential in flexible electronic devices, illustrated with low voltage field-effect transistors for optothermal sensing and flash memories. Electrets with a permanently stored electrical charge are useful to control the threshold voltage in field-effect devices. Ferroelectrets with internally charged voids have been introduced in a ferroelectret field-effect configuration for piezoelectric transducers and microphones. Flexible dielectrics displaying ferro-, piezo- and pyroelectricity are employed in memories and in transducer functions. Finally compliant dielectrics are investigated in elastomer actuators and energy harvesters. The chosen examples show that research on flexible and soft dielectrics is actively pursued in various branches of science, with prospect for future flexible and stretchable electronic products.