Scientists have built a DNA-powered computer that can perform calculations using billions of molecules in a tiny drop of water. The system leverages the laws of physics to create what scientists describe as a computing system that is more efficient than conventional computers widely used today. Instead of continually using energy to force a calculation through a series of processing steps, the DNA computer is designed so that its most “energetically favorable” state is the correct answer. In other words, the computer is built to use less energy than other biological computers, which integrate living cells with traditional hardware, would use to calculate the response. Latest Live Science Videos “The clever thing is that the binding process is competitive: the DNA molecules compete with each other to select a winner, which manages to bind to the scaffold; all the nudging and competition processes information and executes a calculation,” Damien Woods, a computer science professor at Maynooth University in Ireland and a co-author of the study, told LiveScience in an email. “Over time, the system stabilizes in its preferred energy state that encodes the response to the calculation.” The researchers described their system, called the Scaffolded DNA Computer (SDC), in a study published September 16 in the journal Nature. They tested the SDC on 10 programs, including 100-bit calculations. Some calculations, such as 10 + 3, took around 30 seconds to perform for the SDC. You May Like There are several possible long-term applications for SDC, but they are currently speculative, the researchers noted in the study. DNA-based systems could potentially contribute to molecular data storage, energy-efficient forms of computing, or even devices capable of functioning inside living cells. Get the world’s most fascinating discoveries delivered straight to your inbox. “Molecular computers like this are not intended to replace electronic ones, but could be used in biological environments, smart materials, and DNA data storage,” Abeer Eshra, assistant professor of computer science and co-author of the study, told Live Science via email. “Our work is a new direction for DNA data storage, since any data stored in such a system would have natural error-correction properties.” A computer made of DNA The SDC is made of short strands of DNA that interact with a longer DNA scaffold. The strands are placed in a small amount of salt water and then heated and cooled. As DNA strands interact, they assemble into structures according to a set of programmed rules that make up the “calculus.” The DNA strands act like small pieces of a molecular puzzle, and their sequences determine which pieces can join together and at different positions in the longer framework. By designing these binding rules, researchers effectively “program” a calculation. What to read next “Each program corresponds to a set of DNA strands: to program a different calculation or give a different input, we simply select different DNA strands from the refrigerator,” Woods and Eshra told LiveScience in an email. The approach also exploits thermodynamics: the tendency of physical systems to move toward more energetically favorable states. As the mixture is heated and cooled, the strands compete to form the most stable arrangements, energetically favoring the correct configuration. The final structure encodes the response, allowing the molecules to “compute” simply by interacting with each other. DNA molecules interact to “compute” specific calculations. (Image credit: Design Cells via Getty Images) While the DNA computer itself is small, the number of strands involved in the computing process is enormous. “A small drop of liquid contains billions, and sometimes trillions, of DNA strands,” Eshra said in a statement. “These strands interact with each other to produce a result.” A reusable molecular computer Using the SDC, the researchers demonstrated more than 700 calculations throughout their experiments. Its programs included addition; multiplication by 3; division by 2; and eight-bit parity detection, a common type of error correction in computing. Small calculations can be completed in less than a minute, which is surprising given that computing has to go through chemical reactions that take the same amount of time or more. “They’re trivial calculations that you could easily do faster yourself, and a silicon computer would be done in an instant,” Constantine Evans, lead researcher at Maynooth University and co-author of the study, told LiveScience. “Our system uses only a handful of molecules, never really follows an organized process of steps, never takes irreversible steps, and yet ends up with the correct answer. When you think about calculation at the molecular level, reliably doing even those seemingly simple calculations is very difficult.” Larger calculations took much longer. A more difficult sum, on the order of 11 to 34 million, took up to 14 hours. “This demonstrates that the system is programmable, reusable, and, although slow compared to silicon, is fast compared to other DNA computers,” Woods and Eshra wrote in a joint email to Live Science. In addition to being fast, the SDC is reusable. While many previous molecular computers were intended as one-time experiments, the SDC was designed so that the molecules could be used repeatedly. “Many molecular computers to date relied on specially prepared components, or molecular fuels to drive the system, or carefully programmed reactions,” Eshra said. “Instead, our DNA computer works by bringing the molecules together and letting them relax until they reach equilibrium.” Three of the shows were successfully remade up to 24 times. The team even repeated an experiment 1.5 years after the original experiment. The SDC had partially dried, but the researchers were able to repeat the calculations by adding water. For now, however, the work is mainly a demonstration that thermodynamics can be used to make useful calculations. “There’s still a lot of theory to be done!” Eshra said. Broader future directions include “designing structures that are better suited to computation, improving system readout, and investigating potential applications in DNA data storage. We are already working on some of these questions.” Stérin, T., Eshra, A., Evans, C.G., Adio, J., & Woods, D. (2026). A thermodynamically favored molecular computer. Nature, 657 (8132), 646–652. https://doi.org/10.1038/s41586-026-10996-5 Can you match these ancient devices with their images? Find out with our computer science quiz!
