How TPMS Structures Turn Cement into an Energy Generator?

A research team discovered that embedding tiny network-like architectures, called TPMS (Triply Periodic Minimal Surfaces), into cement can turn it into a far more efficient piezoelectric material. The studied structures, Schwarz P and Neovius,{ are three‑dim } are continuous 3‑D lattices that link the piezoelectric ceramic uniformly to the cement.

Using computer simulations, the scientists compared these designs with traditional 0‑3 and 1‑3 models, where the ceramic is either dispersed or placed in isolated columns. At a 20 % ceramic volume fraction, the Neovius structure achieved an average piezoelectric coefficient of 116 pC/N under a 15 kN load—about 12 times higher than the 0‑3 model. Schwarz P showed similar gains.

Why does it work? TPMS geometries create continuous charge‑transfer pathways and spread stress evenly, preventing phase discontinuities. As a result, voltage coefficients and generated voltage rise dramatically: the Neovius composite can reach up to 6.7 V under high loading.

These findings pave the way for “smart” cement that can monitor structural health, harvest energy from vibrations, and make buildings more sustainable.

TPMS architectures are isostatic geometric solutions characterized by zero mean curvature, making them ideal for distributing mechanical loads without stress concentrations. In cementitious composites, the bicontinuous continuity between ceramic phase and cement matrix eliminates the discontinuous interfaces typical of 0‑3 models, reducing charge loss due to percolation effects.

Finite Element Method (FEM) simulations used a linear‑elastic model for cement and a nonlinear piezoelectric model for the ceramic, applying a static 15 kN load on flat surfaces. The analysis revealed that stress distribution σ within the TPMS lattice follows a modified Laplace equation, with peak σ values 30 % lower than in traditional models. This yields higher electromechanical conversion efficiency, quantified by the average d33 coefficient.

From a manufacturing perspective, 3D printing with cement-based inks containing piezoelectric ceramic nanoparticles enables TPMS structures with micrometric resolution. Sintering below 120 °C preserves the piezoelectric properties, while controlled hydration ensures an optimal porous microstructure for charge transfer.

Future applications include integrated sensors for micro‑crack monitoring in bridges, pavements that convert pedestrian vibrations into electricity, and self‑powered facades for IoT systems. The main challenge remains scaling production and long‑term durability in aggressive environments, but early life‑cycle tests show minimal d33 degradation after 10,000 load‑unload cycles.