A research team from IMDEA Materials, the Technical University of Madrid (UPM) and the Alfonso X el Sabio University (UAX) has published a systematic map in Advanced Engineering Materials that combines the mechanical and acoustic properties of TPMS cellular structures.

The study provides a design guide for creating lightweight 3D-printed materials capable of withstanding complex loads while effectively absorbing sound.

Today’s engineering materials are typically either highly resistant or excellent acoustic insulators, but they rarely combine both properties. The conventional solution has been to combine layers of different materials, increasing weight, complexity and cost.

This work presents an alternative by mapping the behaviour of triply periodic minimal surface (TPMS) structures, complex internal architectures that enable both functions to be integrated into a single component.

The study reveals two key findings. From a mechanical perspective, it demonstrates that conventional engineering models, which accurately predict behaviour under compression, fail to predict resistance to shear loading.

The stiffness under these conditions depends on more complex factors, such as the internal connectivity of the structure, an aspect that has received little attention until now. To validate this, the team developed an experimental shear-testing methodology specifically for these materials.

From an acoustic perspective, the research identifies a critical relative density threshold of 25%. Below this density, all architectures behave similarly to porous foams, providing broadband sound absorption.

Above the 25% threshold, however, the specific geometry of the structure becomes crucial. Internal constrictions generate a resonance effect, similar to a network of cavities and necks, enabling much stronger and tunable sound absorption.

The researchers also demonstrated that gradually varying the material density throughout the thickness of the structure can optimise its acoustic performance without increasing its overall weight.

“The true potential of these materials lies not in maximising a single property, such as stiffness, but in their ability to integrate multiple functionalities,” explained Dr. Lucía Doyle, from the School of Engineering, Architecture and Design at UAX and former postdoctoral researcher at IMDEA Materials Institute.

“We have shown that, by controlling the architecture and density, we can design a single lightweight component that provides robust structural support while delivering tailored acoustic performance.”

“This opens a new paradigm for designing lighter and more efficient systems across key industrial sectors,” she added.

The study was carried out with the participation of Profs. Carlos González and Johan Christensen from IMDEA Materials Institute, and Prof. María Ángeles Navacerrada from UPM.

These findings establish the foundations for the precision engineering of multifunctional materials.

The property map developed by the researchers will serve as a design guide to help engineers select and optimise TPMS architectures for specific applications, ranging from lighter and quieter components for the aerospace and automotive industries to structural building elements with integrated acoustic insulation.

This research received funding from the Horizon 2020 Marie Skłodowska-Curie Actions programme (Grant Agreement No. 101106955).