A team of engineers from the Delft University of Technology and Brown University have invented strings that can almost vibrate forever at room temperature. Previous efforts to develop strings with such extremely low energy dissipation rates have accomplished similar successes but only at near absolute zero temperatures, dramatically limiting their potential applications.
The engineers behind the groundbreaking invention say these types of strings also allow much less “noise” to enter in, meaning they could revolutionize the detection of gravitational waves at the macroscopic scale while ushering in a whole new generation of ultra-sensitive detectors operating at the nanoscale. The team says they also hope to create other shapes beyond strings, which could open up even more potential uses.
“Imagine a swing that, once pushed, keeps swinging for almost 100 years because it loses almost no energy through the ropes,” explained associate professor Richard Norte, one of the authors on the paper outlining the achievement. “Our nanostrings do something similar, but rather than vibrating once per second like a swing, our strings vibrate 100,000 times per second.”
Richard Norte.
The Secret behind the Strings That Can Almost Vibrate Forever is the Scale
According to the study authors, the key to their low dissipation strings lies in their scale. Structures this infinitesimally small react differently to things like weight and gravity, allowing them to possess incredible and valuable properties that would be impossible in larger devices.
In this particular case, the team used cutting-edge nanofabrication techniques to create strings that are three centimeters long but only 70 nanometers thick. For comparison, the researchers say this is the macroscale equivalent of making guitar strings out of glass that “suspend” for nearly half a kilometer with almost no sag.
“This kind of extreme structures are only feasible at nanoscales where the effects of gravity and weight enter differently,” said Dr. Andrea Cupertino, who led the team’s experiments. “This allows for structures that would be unfeasible at our everyday scales but are particularly useful in miniature devices used to measure physical quantities such as pressure, temperature, acceleration, and magnetic fields, which we call MEMS sensing.”
Traditionally, creating such precision structures at any scale would require hundreds of not thousands of prototypes before the final working version would emerge. Such experiments not only consume significant resources but can add years to the effort. However, the engineers behind the strings that can almost vibrate forever say that advancements in machine learning and simulation software allowed them to model, design, test, and construct generation after generation of structures virtually instead of having to build each and every iteration.
“Our approach involved using machine learning algorithms to optimize the design without continuously fabricating prototypes,” noted lead author Dr. Dongil Shin, who developed these algorithms with Miguel Bessa. As noted, this rapid and precise process saved the engineers significant time and money.
Detecting Gravitational Waves Among Numerous Potential Applications
With their experiments and results published in the journal Nature Communications, the team of engineers behind the strings that can almost vibrate forever say there are a number of potential applications for the inventions, especially since they can operate at room temperature.
For example, tools that detect gravitational waves, like Cal Tech’s Laser Interferometer Gravitational-Wave Observatory (LIGO), which confirmed Einstein’s theories about gravitational waves almost 100 years after they were first proposed, could see dramatic improvements in sensitivity using these types of ultra-sensitive strings. That work earned the researchers behind the detection a Nobel Prize in 2016.
The Debrief previously reported on one interesting concept: using LIGO to hunt for the telltale signatures of warp spacecraft. Such an effort would directly benefit from increased device sensitivity.
“The implications of these nanostrings extend beyond basic science,” explains a press release announcing the breakthrough invention. “They offer promising new pathways for integrating highly sensitive sensors with standard microchip technology, leading to new approaches in vibration-based sensing.”
Next, the team says they will investigate creating other extremely low-energy diffusion shapes beyond strings, which could significantly expand their potential uses. This could include accelerometers used in inertial navigation and designing an ultra-sensitive drum head for “next-generation” microphones.
“By blurring the line between macroscopic and nanoscale objects, these centimeter-scale nanomechanical systems challenge our conventional intuitions about fabrication, costs, and computer design and promise to give us innovative capabilities that have not been available at smaller scales,” the study authors conclude.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.