Future Among the Stars: Micro Fluidic Microbial Fuel Cells

Space has evolved from a realm of scientific curiosity into a contested domain where nations compete for strategic advantage. As the U.S. Space Force Chief, Gen. Chance Saltzman, emphasized in a lecture on April 1, 2025, at the U.S. Naval War College, space is now a war fighting domain requiring innovative technologies to ensure resilience and operational independence. Among the most promising advancements in this arena are Micro Fluidic Microbial Fuel Cells (MFMFCs)—compact, bioelectrochemical systems that harness electrogenic bacteria to convert organic waste into electricity. These devices offer a sustainable solution to two critical challenges in space: power generation and waste management. With applications spanning military operations and civilian exploration, MFMFCs could redefine how humanity sustains itself beyond Earth while also contributing to sustainability goals on our home planet. This article delves into the mechanics of MFMFCs, their strategic significance, their potential uses in space, and the hurdles that must be addressed to unlock their full potential.

What Are MFMFCs and How Do They Work?

At their core, MFMFCs are a fusion of biology and engineering. They rely on electrogenic bacteria, such as “Shewanella oneidensis”, which metabolize organic waste—think food scraps or human waste—and release electrons as a byproduct. These electrons are captured to produce an electrical current, effectively turning waste into a renewable energy source. What sets MFMFCs apart from traditional microbial fuel cells is their micro-fluidic design. Channels within these devices, ranging from 1 to 1,000 micrometers in size, enhance efficiency by maximizing the surface area-to-volume ratio. Unlike conventional systems, MFMFCs exploit the laminar flow of fluids in these tiny channels, eliminating the need for ion exchange membranes. This reduces problems like membrane degradation and fuel crossover, making the technology lightweight, compact, and cost-effective—attributes that are invaluable for space missions where payload weight is a limiting factor.
On Earth, microbial fuel cells have been refined for applications like waste water treatment, achieving power densities of up to 1,000 milliwatts per square meter. However, adapting this technology for space introduces unique considerations, particularly the influence of microgravity on fluid dynamics and bacterial behavior. Despite these unknowns, the fundamental promise of MFMFCs remains: a sustainable, dual-purpose system that generates power while managing waste.

Strategic Importance in a Contested Space Domain

The militarization of space has heightened the need for technologies that reduce dependence on Earth-based resupply, a vulnerability in contested environments. Gen. Saltzman’s lecture underscored this reality, highlighting the importance of defending space capabilities and ensuring operational continuity amid growing threats. MFMFCs address this strategic imperative by providing a self-sufficient power source that recycles organic waste into energy. For military satellites—vital for communication, navigation, and surveillance—this could mean extended operational lifespans beyond the limits of solar panels or batteries, which are susceptible to degradation or enemy interference like anti-satellite weapons. By integrating MFMFCs, satellites could gain an additional layer of resilience, enhancing their ability to function in hostile conditions. For crewed missions, the technology’s benefits are even more pronounced. Prolonged operations, whether in orbit or on lunar and Martian bases, demand solutions that minimize logistical burdens. MFMFCs offer a closed-loop system that not only generates electricity but also reduces waste accumulation—a persistent challenge in space. This dual functionality aligns with the U.S. Space Force’s vision of maintaining space superiority through innovative, sustainable technologies.

Military Applications: Enhancing Resilience

The military potential of MFMFCs lies in their ability to support extended missions in remote and contested environments. By converting waste into energy, they decrease the need for frequent resupply missions, a logistical challenge that becomes a liability in space-based conflicts. Imagine a lunar outpost or a Martian military habitat: MFMFCs could power critical systems—life support, communication, defense infrastructure—while simultaneously managing organic waste produced by personnel. This operational independence is a game-changer, reducing vulnerabilities and enabling the Space Force to project power in domains where traditional energy sources fall short. The technology’s lightweight and compact nature further enhances its military utility. Every gram launched into space comes at a premium, and MFMFCs’ efficient design makes them a practical addition to spacecraft, satellites, and planetary bases. As the Space Force develops offensive and defensive capabilities to counter space-enabled threats, as discussed in a 2025 symposium on space superiority, MFMFCs could play a pivotal role in sustaining these operations over time.

Civilian Applications: Sustainable Exploration

Beyond military use, MFMFCs hold immense promise for civilian space exploration. NASA’s Artemis program, aiming for a sustainable human presence on the Moon by the late 2020s, exemplifies the need for technologies that support long-term habitation. International efforts, such as the China/Russia-led International Lunar Research Station, similarly prioritize sustainability. MFMFCs fit seamlessly into these ambitions by enabling closed-loop systems that recycle waste into energy, addressing both power generation and waste management—two of the biggest hurdles for extraterrestrial habitats. Consider a lunar base: astronauts produce organic waste daily, and without a way to manage it, this waste accumulates, straining resources and risking contamination. MFMFCs turn this liability into an asset, generating electricity to power habitat systems while reducing waste volume. This capability is equally vital for Mars missions, where resupply from Earth is impractical due to distance and cost. NASA’s 2024 Space Sustainability Strategy emphasizes minimizing orbital debris and ensuring the long-term viability of space operations, and MFMFCs contribute by preventing waste buildup in space. Moreover, the technology’s impact extends to Earth. Its potential to enhance waste water treatment and renewable energy production aligns with global sustainability goals, such as the United Nations’ Sustainable Development Goal 7 for affordable and clean energy. This dual-use nature makes MFMFCs a bridge between space exploration and terrestrial environmental challenges.

Challenges and Ethical Considerations

Despite their potential, MFMFCs face significant obstacles. A major unknown is how microgravity affects their performance. On Earth, gravity aids in mixing substrates and transporting nutrients to bacteria, but in space, these processes depend on diffusion alone, which could lower efficiency. Bacterial behavior, including motility and biofilm formation, may also change in microgravity, impacting electron transfer and power output. To date, no experiments have tested MFMFCs in space, leaving a critical gap in understanding. A proposed experiment on the International Space Station, weighing less than 500 grams and costing $100,000, could measure power output over a week, providing essential data to refine the technology for space use. Scaling MFMFCs for practical applications presents additional hurdles. Laboratory prototypes show promise, but real-world deployment requires advances in electrode materials, operational stability, and power density. A 2018 review of microbial fuel cell scale-up noted challenges like electrode fouling and the need for durable, cost-effective components—issues magnified in space, where maintenance is limited, and reliability is non-negotiable. Ethical concerns also loom large. Even with reduced waste, deploying MFMFCs in space raises questions about contaminating extraterrestrial environments. NASA’s focus on planetary stewardship, outlined in its sustainability strategy, emphasizes preserving the Moon and Mars for future generations. Any technology used in space must adhere to strict guidelines to avoid irreversible harm, balancing innovation with responsibility.

A Path Forward

MFMFCs represent a convergence of necessity and ingenuity, offering a sustainable solution for an era where space is both a frontier and a battlefield. For military operations, they provide resilience and independence, countering vulnerabilities in contested domains. For civilian exploration, they enable long-term habitation by tackling power and waste challenges. Their terrestrial applications further amplify their value, contributing to global sustainability efforts. Investing in MFMFCs is not just practical—it’s essential. As space becomes increasingly contested, self-sufficient technologies will define humanity’s ability to thrive beyond Earth. Overcoming the technical and ethical challenges ahead will require concerted effort, but the payoff—operational security, sustainable exploration, and environmental stewardship—is transformative. In the words of Gen. Saltzman, space demands innovation to meet its threats. MFMFCs rise to that challenge, embodying the ingenuity needed to secure our future among the stars.