Abstract: An in-ear device comprises a transducer section, a front volume section, and a rear volume section. The transducer section includes a frame and piezoelectric actuators coupled to the frame. The piezoelectric actuators are configured to generate an acoustic pressure wave. The transducer section includes a first side and a second side, the second side being opposite the first side. The front volume section is coupled to the first side to form a front cavity, the front volume section including an aperture from which the generated acoustic pressure wave exits the front volume section towards an ear drum of a user. The rear volume section is coupled to the second side to form a rear cavity. The transducer section, the front volume section, and the rear volume section are configured to fit entirely within the ear canal.

Abstract: A method of forming a voided polymer includes forming a polymerizable composition containing a polymer precursor and a solid templating agent, forming a coating of the polymerizable composition, processing the coating to form a cured polymer material having a solid phase in a plurality of defined regions, and removing at least a portion of the solid phase from the cured polymer material to form a voided polymer layer.