Scientists at Northwestern University have developed a new liquid material that harvests, stores, and releases energy within a single system.

Powered by sources like light or electricity, the metal- and plastic-free material physically shape-shifts from a fluid into an energy-dense gel to store power, then resets to a liquid simply by exposure to open air. 

This sustainable, adaptable platform eliminates the need for hardware components, opening new doors for clean energy and soft electronics.

“Our material’s ability to store and release energy on demand could make it useful for energy storage, environmental remediation and next-generation soft electronics,” said Samuel I. Stupp, the study’s senior author. 

Bio-inspired technique

To build it, the team looked inside our own bodies and drew inspiration from the cell’s cytoskeleton.

A cellular skeleton is incredibly dynamic. It constantly constructs, breaks down, and reconstructs itself to help the cell move and divide.

Northwestern researchers designed a material that physically builds, dismantles, and rebuilds itself to manage energy. 

Powered by external electrons from sources such as sunlight or X-rays, the initial yellow liquid transforms into an energy-rich black gel that can store energy for months and drive chemical reactions. 

The entire process resets seamlessly when exposed to open air, which dissolves the gel back into its liquid state, allowing it to be recharged and reused repeatedly.

“Living systems are remarkably dynamic,” Stupp said. “They constantly build structures, break them apart, and rebuild them. We wanted to create a synthetic material that behaves in a similar way while performing useful functions.”

To overcome the limitation where energy harvesting, storage, and usage require separate devices, researchers used supramolecular materials that self-organize into larger networks. 

A custom molecule, ANI-MV, was designed. It integrates two functional components into a single system: an amino naphthalene aromatic unit (ANI) that responds to light, and a methyl viologen (MV) unit that stores the captured electrons.

Use in soft electronics

When the light-responsive ANI portion absorbs energy, it transfers electrons to the MV portion, causing neighboring molecules to strongly attract and form pairs called pimers. 

These pimers organize into semiconducting nanoscale ribbons with free-moving, delocalized electrons that eventually entangle into a black gel. 

This network stores electrons throughout its structure, marking the first real-world example of a supramolecular polymeric pimer built from electron-storing molecular pairs.

In laboratory experiments, researchers demonstrated the material’s remarkable versatility by triggering its transformation from a yellow liquid into an energy-rich, conductive black gel using chemical fuel, light, electricity, or X-rays. 

As light can selectively target the fluid, scientists were able to print microscopic conductive patterns that completely vanish once exposed to open air, which reverts the gel back into non-conductive liquid clusters. 

Furthermore, this stored energy can be transferred to oxygen, generating highly reactive molecules that enable the gel to power chemical reactions in complete darkness. This process is known as dark photocatalysis.

“Most light-driven materials stop working when the light source is gone,” Stupp said. “Our material enables a form of ‘dark photocatalysis.'”

Researchers envision this material powering applications ranging from environmental remediation and clean energy to adaptive soft electronics.

The study was published in the journal Chem on June 11.

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In the urgent race to cool a warming planet, scientists have long dreamed of turning a major villain into a valuable asset. The challenge has always been the sheer amount of energy required to force stable greenhouse gases into a more useful state.

Now, University of Nottingham scientists have developed a solar-powered reactor that couples two novel catalyst materials to drive two independent reactions at once. 

Powered entirely by sunlight, the system simultaneously transforms carbon dioxide into a valuable chemical while converting biomass waste into the essential building blocks for sustainable plastics.

This device accomplishes the feat by extracting two distinct, valuable chemical products from the energy of a single photon of light.

The split-chamber reactor

The machine is known as a bias-free photoelectrochemical (PEC) reactor. 

It works through a twin-compartment design, effectively splitting a single solar interaction down the middle to achieve two goals at once.

The dual-compartment reactor uses a single photon of sunlight to drive a highly efficient chain reaction. 

“At the heart of the process is a nanostructured photoanode made of carbon nitride and tungsten oxide semiconductors, enhanced with a cobalt oxide layer, which is coupled to a cathode in the second compartment,” said Dr Madasamy Thangamuthu, Research Fellow at the School of Chemistry, University of Nottingham, who designed the PEC reactor and catalysts. 

The solar-driven process begins when a photon of light strikes the photoanode, generating a freed electron and an atomic vacancy called a hole. 

While the electron travels to the cathode to reduce carbon dioxide, the remaining hole simultaneously oxidizes the biomass molecule 5-Hydroxymethyl-2-furoic acid (HMFA), thereby executing two distinct chemical upgrades at the same time.

When light hits the first compartment, it oxidizes a biowaste molecule into a precursor for next-generation plastics. This reaction releases an electron, which travels to the second compartment to reduce carbon dioxide into formate, a versatile chemical used in textiles, paints, and pharmaceuticals.

Tailored for the real world

Operating purely on solar energy, without requiring external heat or electricity, the reactor achieves approximately 93 percent conversion for carbon dioxide and 95 percent oxidation for biomass. 

The use of photon energy offers a highly efficient and sustainable blueprint for zero-emission chemical manufacturing.

Furthermore, many modern lab breakthroughs use rare, hyper-expensive metals like platinum or iridium to drive their chemistry. These materials look wonderful in academic journals but are completely impractical for global industrial scaling.

The Nottingham team engineered their materials entirely from earth-abundant, inexpensive elements. 

The scientists kept production costs low while maintaining high efficiency rates through a unique method: they assembled the catalyst‘s metal atoms into custom-tailored sizes and shapes directly on the reactor surfaces.

A full life cycle assessment has already validated the system’s low-carbon footprint. 

The long-term vision is a decentralized manufacturing network. These modular reactors can eventually be connected directly to active factory smokestacks and local agricultural biorefineries.

Ultimately, the team views this discovery as a vital step toward meeting global net-zero targets by directly harnessing solar energy to tackle the dual challenges of greenhouse gas reduction and waste valorization.

The study was published in the journal Communications Materials on June 12.

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