Mimicking Plant Stems for Power Generation

Inspired by nature and engineered for the built environment, researchers have created a cement-based material that does more than support weight—it generates and stores power. In a study published recently in Science Bulletin, this innovation could transform ordinary infrastructure into self-powered systems for smart cities.

At this year’s SynBioBeta: The Global Synthetic Biology Conference, a related session entitled “Conquering Carbon Emissions From the Concrete Industry”  will discuss some of the current challenges new concrete structures face and how bioengineered materials could be the solution. 

The team, led by Professor Zhou Yang at Southeast University, developed a cement-hydrogel composite that dramatically outperforms all known cement-based thermoelectric materials. Drawing inspiration from the layered internal structure of plant stems, this bio-inspired material achieves a remarkable Seebeck coefficient of −40.5 mV/K and a figure of merit (ZT) of 6.6×10⁻²—surpassing existing benchmarks by tenfold and sixfold, respectively.

The researchers tackled a fundamental limitation in cement's ionic thermoelectric performance: the challenge of restricted ion mobility in the dense cement matrix. "The disparity in diffusion rate between cations and anions within cement pore solution due to variations in interactions with pore walls endows cement with inherent ionic thermoelectric properties," the authors stated. "However, the isolation of pores by the dense cement matrix hinders the rapid transportation of ions with superior diffusion rates, impeding the enhancement of mobility difference between ions and limiting the enhancement of Seebeck coefficient."

Their solution? A multilayered structure composed of alternating cement and polyvinyl alcohol (PVA) hydrogel layers. This configuration enables. Hydrogel layers provide highways for hydroxide ions (OH⁻), while the cement-hydrogel interfaces form strong bonds with calcium ions (Ca²⁺) and weaker ones with OH⁻. This engineered disparity in ion diffusion boosts the thermoelectric effect.

Built-In Energy Storage and Smart Infrastructure Applications

The innovation goes beyond power generation. Thanks to its multilayered architecture, the composite exhibits enhanced mechanical strength and intrinsic energy storage—allowing it to serve as both an energy harvester and a storage system. This dual capability opens the door to applications in smart buildings, roads, and bridges, where the infrastructure itself could power embedded sensors and wireless systems.

"The CPC’s multilayer structure yields abundant interfaces, providing ample interaction sites that maximize the contribution of cement ions to thermoelectric performance," the researchers concluded. "The biomimetic structure and interfacial selective immobilization mechanism may pave the way for the design and fabrication of high-performance ionic thermoelectric materials."