Towards a new generation of soft and conformable acoustic devices based on electroactive polymers

ended

The project operates in the key European research area of enabling technologies based on Advanced Materials. It deals with a class of smart electroactive polymers, called dielectric elastomers (DEs), which can be promisingly employed to develop soft low-cost electrostatic machines able to respond to electrical stimuli with high deformations and large actuation bandwidth. In the field of acoustics, DEs might enable the development of new loudspeakers in which the vibrating diaphragm and the actuator are combined into a soft membrane that can be adapted to arbitrary shapes or integrated into wearable textile structures. This project will develop radically new DE acoustic diaphragms exploiting the paradigms of distributed surface actuation (DSA) and self-sensing. DSA will allow a regulation of diaphragms vibrations via localised excitation of the active surface, allowing a fine control of the acoustic response. Self-sensing will allow DE devices to work both as sound generation sources and sound pressure sensors, opening new perspectives in the field of active noise control and acoustic characterisation of environments. Theoretical background on continuum vibrations in DE membranes will be first developed through modelling and experimental investigation with high-end laser vibrometry equipment. Multi-physics models of the acoustic-structure interaction of the DE diaphragms will be set-up. Diaphragms with DSA will be deployed through the segmentation of the active DE surface into arrays of independently-controlled portions via screen printing techniques. Algorithms for self-sensing of the vibrations generated by electrical or acoustic signals will be developed, which rely on simple electrical measurements of the active areas electrical variables. Finally, a prototype of a DE acoustic transducer, capable to work both as a speaker and a microphone, will be built, and its performance will be optimised leveraging on the investigated features of DSA and self-sensing.