Reducing the noise produced by and structural weight of airplanes are currently significant challenges for the aerospace industry. To overcome these challenges, additive manufacturing is investigated to create lighter and more efficient sound-absorbing structures compared to the technologies currently employed (e.g., perforated honeycomb cell sandwich panels). The present work uses the concept of Helmholtz resonators combined with Fused Filament Fabrication (FFF) 3D printing process to produce high-performance acoustic structures. Several different Helmholtz resonators are combined to create a multi-resonator of five cavities, 3D printed using low/medium melting temperature thermoplastics (i.e., polylactic acid, polyamide) as a proof of concept. Different designs of multi-resonators are tested in an impedance tube that measures the acoustic absorption coefficient at different frequencies. The printed structures exhibit a sound absorption of at approximately 500 Hz located between 700-1200 Hz. Those structures are then adapted into sandwich panels, composed of a core, a facesheet and a perforated facesheet, and manufactured in one single step. The panels, 3D printed using various materials, are tested in three-point bending. The target is to reduce the premature delamination between the core and the sheets by slightly adjusting the geometry of the acoustic structures. Once the performance of our structures is reaching the targeted values set by our industrial partner, their manufacturing will evolve from low to high temperature thermoplastic systems with reinforcements and from flat to curved configurations using a custom-made 6-axis robotic system. Keywords: 3D printing, additive manufacturing, acoustic, Helmholtz resonators, sandwich panels