Cells Contain Battery Droplets

Electricity is at work in
living cells, helping them
form the molecules of life

Cells are not simple like Darwin thought. The amount of organization inside a cell continues to astonish scientists. A few years ago, molecular condensates were discovered within the nucleus (see my articles here and here at Science & Culture Today). These “membraneless organelles” or “droplets”, formed during natural phase changes, bring together molecular building blocks with their enzymes and RNA codes, facilitating the construction of complex molecules for life. Now, a research team at Washington University at St. Louis has discovered another wonder about these condensates: their boundaries are electric!

(Note: the authors will try to sneak “evolution” into the story, but it’s a fallacious use of terms, as we shall see.)

Tapping the engines of cellular electrochemistry and forces of evolution (23 Jan 2026, Washington University at St. Louis). Reporter Leah Shaffer speaks of condensates as “constantly shifting, membrane-less organelles that govern how a cell functions.” They are aided by phase changes in “intrinsically disordered proteins” that used to be thought of as mistakes or junk. No; they have important functions. Professor Rohit Pappu and his colleague Yifan Dai discovered that electrical voltages play key roles in the formation of condensates.

In the new research, Dai outlines how condensates can act as “battery droplets.” Inside a battery, the real action happens at the interface — the thin boundary where the electrode and electrolytes touch. An “interfacial” electric field drives chemical reactions within a cell in a similar manner, converting chemical energy to electrical energy.

This electrical energy is measurable. The researchers believe they could even tap into this miniature power source to design therapeutic molecules and other useful things.

Dai’s team demonstrated that microscale “engines” can drive a bit of alchemy, producing gold and copper nanoparticles directly in living cells. Such “biohybrid” devices could be used to degrade pollution in wastewater. Further, through the same protein materials, they show how the redox reactions can be exploited to kill bacteria without using antibiotics, which could lead to many new medical devices to improve human health.

A Closer Look at These “Soft Battery Droplets”

The press release tells how these “microscale engines” work like “soft battery droplets” that store and release electrochemical energy on demand, “giving synthetic biologists a dynamic new way to power signals and reactions” according to Dr Dai.

Although they lack the metal plate electrode used in batteries, the proteins still have an interface that serves the same purpose: a surface where a condensate meets the surrounding solvent, where certain ions and molecules prefer one side over the other. That uneven distribution creates tiny electrical imbalances, like miniature voltages inside the cell.

This voltage can drive electrochemical reactions like the metal electrode, thereby powering electron transfer. And because these droplets move, bump into membranes, and fuse with each other, their interfaces are constantly rearranging — charging and discharging in bursts.

What’s Evolution Got to Do With It?

Try as they might to insert “evolution” into the story, they commit the logical fallacy of equivocation. They use the term “directed evolution” as a means of steering these soft battery droplets for human use. What they are really doing is applying intelligent design. They have foresight and a goal.

“We designed the evolution-based assay and selection strategies to connect cellular survival and the behaviors of the disordered proteins, then put them into different temperatures or other selective pressures, and let it go,” Dai said. “We let nature do the work to give us a sequence that can behave and let them survive.”

“Directed evolution” is a contradiction in terms. Picking out the most useful products from searches through natural phenomena is characteristic of intelligence, not mindless evolution. They are steering the molecules at every step. Only a mind can pick out a sequence in a random distribution and decide that it meets the criteria for a human need or desired technology. Darwin has nothing to say about this.

For those interested in this fascinating subject of “soft battery droplets” in living cells, the scientists published their work in Nature Materials:

Electrogenic protein condensates as intracellular electrochemical reactors (Yu et al, Nature Materials, 15 Jan 2026). From the abstract:

Here we show that genetically encoded biomaterials that can undergo self-assembly into protein condensates can be engineered to function as electrochemical reactors. We establish the fundamental principles that govern the sequence–electrochemical property relationship of protein condensates, thereby programming their electrogenic behaviours. We demonstrate the applications of protein condensates in various electrochemical reactions in vitro. We also deploy these condensates in biological cells as living materials for intracellular nanoparticle synthesis, pollutant degradation and antibiotic-free inhibition of bacteria through artificial ferroptosis. These intrinsic electrogenic materials offer a biomaterial platform that could be used as a clean and sustainable energy source for the development of next-generation bioelectrochemical devices.