Researchers from St. Olaf College and Syracuse University have built mechanical computers made entirely of common materials that can perform simple calculations without electricity or batteries. Led by St. Olaf College physics professor Joey Paulsen, the team used steel springs and bars to create devices that store and process information by physically responding to motion and force. One machine counts how many times it is moved, another determines whether it has been pushed an odd or even number of times, and a third remembers whether it experienced a medium or large force, demonstrating that everyday materials can both retain memory and perform basic computation.
“We now have a rational way of building these machines that can perform simple computations without a computer chip or a power source,” Paulsen said.
Key findings from the research include:
- Mechanical computers can perform simple computations without a computer chip or power source.
- Mechanical computers are able to harvest their power from physical force, rather than electricity.
- Proof of design that mechanical computers could be a viable alternative to conventional computers in harsh settings—such as extreme temperatures or exposure to corrosive chemicals—when only simple computations are needed.
“Our results are one step towards designing materials that can sense their environment, make a decision, and then respond,” said Paulsen. “Frequently called smart materials, what we learned could help improve people’s lives by having more responsive artificial limbs or tactile rooms.”
Paulsen recommends that future research on mechanical computers focus on understanding their limitations and scalability. Under his leadership, St. Olaf students are currently testing how the state of one rotor affects its interaction with a second rotor –– and potentially a third. This research will continue in the coming months, with opportunities for students to participate through the college’s Collaborative Undergraduate Research and Inquiry (CURI) program.
For more information: Nature Communications
Image: St. Olaf College students Faten Abu Al Ardat ‘27 and Harry Maakestad ‘26 work on building the mechanical computer.
