Creating the First Rechargeable “Living Cement”

How bacteria, cement and energy storage are being combined into one material system

A research-based feature article | October 2026

Concrete has usually been treated as an inert material: strong, durable and passive. A new line of research challenges that assumption by placing living electroactive bacteria inside a cement matrix and using the resulting composite as a rechargeable supercapacitor. The approach, demonstrated by researchers at Aarhus University, is not a commercial building product yet. It is a proof-of-concept for construction materials that could bear loads, exchange electrons and recover part of their energy-storage performance after biological activity declines. [1]

The central idea is simple but technically ambitious. Instead of adding a separate battery room to a building, the structural material itself could become part of the energy system. Walls, foundations or bridge elements might one day store short bursts of electricity from solar panels and deliver power to sensors, lighting or other low-power devices. The scientific challenge is to make those functions coexist without sacrificing mechanical integrity, biological stability or safe operation.

Figure 1. Scanning-electron-microscope image of Shewanella oneidensis associated with the Aarhus University living-cement research. Image: Qi Luo / Aarhus University. [1]

What makes the cement “living”?

The Aarhus team used Shewanella oneidensis MR-1, a bacterium known for extracellular electron transfer. This biological process allows the cells to move electrons to external surfaces rather than keeping all of their redox chemistry inside the cell. When the microbes are distributed through a cement scaffold, they help form a charge-transfer network that can store and release electrical energy. [1] [2]

The term “living” describes the active biological component, not a claim that a finished wall would behave like an organism. The cement provides a rigid, porous environment; the microorganisms contribute electrochemical activity; and a microfluidic network supplies nutrients. Proteins, vitamins, salts and growth factors can be delivered to support the cells or reactivate part of the system after activity has faded. [1]

The device is closer to a supercapacitor than to a conventional lithium-ion battery. Supercapacitors are valued for fast charge and discharge and for their ability to survive many cycles, although they usually store less energy per kilogram than batteries. In the published prototype, the microbial cement retained 85% of its capacitance after 10,000 cycles. After microbial inactivation, residual conductive and redox-active networks still supported charge storage; nutrient delivery restored up to 80% of the original capacitance. [2]

Figure 2. Graphical abstract from the peer-reviewed study: electroactive microorganisms are integrated into a cement matrix, while an embedded microfluidic pathway supports reactivation. [2]

A recharge cycle that depends on biology

The recharging concept has two layers. Electrical charging stores energy in the composite’s electrochemical network. Biological reactivation restores the microbes’ ability to participate in charge transfer when nutrients are introduced. That distinction is important: the material does not create free energy, and feeding the microbes is not the same as plugging a battery into a wall. It is a maintenance pathway designed to recover function that would otherwise decline.

The researchers connected six cement blocks in series and generated enough output to power an LED. They also reported that the prototype continued to store and discharge electricity under freezing and elevated-temperature tests. These demonstrations show feasibility at laboratory scale, but they do not yet prove that a building wall can replace a grid battery. Long-term performance under humidity cycles, mechanical loading, contamination, variable nutrient delivery and construction tolerances still needs to be established. [1] [2]

A major engineering question is containment. Shewanella oneidensis is a laboratory organism used in environmental and electrochemical research, yet any building-scale design would need clear biosafety controls, predictable nutrient pathways and an end-of-life plan. Designers would also need to specify whether the biological system remains active, becomes dormant or is intentionally inactivated once the structure is commissioned.

Two routes toward energy-storing infrastructure

The Aarhus approach is biohybrid: microorganisms provide electrochemical functionality inside cement. A parallel route, developed by MIT, uses electron-conducting carbon concrete, or ec³. That material combines cement, water, ultrafine carbon black and electrolytes to create a conductive nanonetwork. It is not a biological system, but it shows why structural energy storage is attracting attention beyond one research group. [3]

MIT reported that an optimized ec³ formulation can store more than 2 kilowatt-hours per cubic meter, roughly enough to power a refrigerator for a day. The team also built a small arch that carried its own weight and additional load while powering an LED. When the load changed, the light flickered, suggesting that electrical output could potentially reveal changes in structural stress. Batteries still offer higher energy density, but carbon-cement systems can be shaped as slabs, walls, domes or vaults and may last as long as the structure itself. [3]

These technologies should not be collapsed into one “concrete battery” category. Microbial cement depends on living or reactivatable electroactive communities and nutrient delivery. Carbon-cement supercapacitors depend on conductive carbon networks and electrolytes. Both seek multifunctional construction materials, yet their environmental profiles, controls, maintenance needs and failure modes are different.

Figure 3. MIT ec³ arch prototype powering an LED while carrying load, illustrating the structural-energy-storage concept. Image: MIT EC³ Hub, via MIT News. [3]

Biology can also protect the structure

Energy storage is only one branch of bio-enabled cement research. The University of Bath has investigated self-healing concrete containing bacterial spores and a growth medium. When a crack allows water and oxygen to enter, the bacteria become active and help produce calcium carbonate, or limestone, that seals the opening. The team has also studied bacteria adapted to lower temperatures. [4]

Self-healing and energy storage could eventually be designed as separate layers or complementary functions, but combining them in one mix would be demanding. A material that heals cracks, transfers electrons and carries structural loads would need carefully controlled pores, chemistry and moisture. Each added function can change strength, durability, cost and recyclability. The right question is not whether cement can do everything, but which functions deliver measurable value in a specific building or infrastructure setting.

Closing Thoughts

The most compelling aspect of rechargeable living cement is not the image of a house that behaves like a giant battery. It is the shift in how construction materials are defined. Cement can be treated as a platform that combines load-bearing, sensing, repair and energy functions. That shift is valuable only if the added functions remain safe, affordable and useful over decades. For now, the Aarhus result is a strong laboratory demonstration and a credible invitation to rethink infrastructure, not a finished replacement for batteries.

What does this look like in practice?

A realistic early application could be a small, monitored structural element rather than an entire building. A wall panel or foundation block could contain microbial cement electrodes, fluid channels for nutrient delivery, wiring, temperature sensors and a control unit. Solar power could charge the device; the cement supercapacitor could provide short-duration power to environmental sensors, structural-health monitoring or emergency indicators. Engineers would compare its energy output, maintenance demand and service life with a conventional battery installed beside the structure.

A second pathway is hybrid construction. Carbon-cement supercapacitor elements could provide higher electrical performance, while bacterial concrete could target crack management in selected zones. This modular approach would make testing, replacement and regulation easier than asking one material to perform every function at once.

What is the relevance of this?

Buildings and infrastructure already occupy enormous volumes and connect to energy networks. If part of that physical mass can also store electricity or support autonomous sensing, the built environment could become more flexible during renewable-energy fluctuations. Structural storage would not remove the need for grid-scale batteries, but it could reduce the number of separate components required for local, short-duration functions.

The wider relevance is material efficiency. A bridge, road or wall that performs more than one useful job can change how designers evaluate cost, maintenance and carbon. The research also exposes the limits of that ambition: cement production remains carbon-intensive, biological systems need control, and laboratory performance does not automatically translate into safe construction practice. The next advances will be judged by durability, life-cycle impact and reliability at real scale.

References

1. Aarhus University, “Living cement: scientists turn bacteria-infused cement into energy-storing supercapacitors,” 11 September 2025. https://bce.au.dk/en/currently/news/show/artikel/living-cement-scientists-turn-bacteria-infused-cement-into-energy-storing-supercapacitors

2. Q. Luo et al., “Living microbial cement supercapacitors with reactivatable energy storage,” Cell Reports Physical Science, vol. 6, issue 9, article 102810, 2025. https://doi.org/10.1016/j.xcrp.2025.102810

3. MIT News, “Concrete ‘battery’ developed at MIT now packs 10 times the power,” 1 October 2025. https://news.mit.edu/2025/concrete-battery-now-packs-ten-times-power-1001

4. University of Bath, “Using bacteria to create spontaneous self-healing concrete.” https://www.bath.ac.uk/case-studies/using-bacteria-to-create-spontaneous-self-healing-concrete