Engineers have learned how to create tiny earthquakes on a microchip—and it could change how smartphones are built.
Engineers have developed a new way to create extremely small vibrations that resemble miniature earthquakes.
At the center of the work is a device called a surface acoustic wave phonon laser. In the future, this technology could support the development of more advanced chips for cellphones and other wireless electronics, helping make those devices smaller, faster, and more energy efficient.
The research was led by Matt Eichenfield, an incoming faculty member at the University of Colorado Boulder, together with collaborators from the University of Arizona and Sandia National Laboratories. Their results were published Jan. 14 in the journal Nature.
The device relies on a physical effect known as surface acoustic waves, or SAWs. These waves behave similarly to sound waves, but instead of traveling through the bulk of a material, they move only along its surface.
During an earthquake, large SAWs spread across the Earth’s surface, shaking structures and causing damage.
At far smaller scales, however, SAWs are already woven into everyday technology.
“SAWs devices are critical to the many of the world’s most important technologies,” said Eichenfield, senior author of the new study and Gustafson Endowed Chair in Quantum Engineering at CU Boulder. “They’re in all modern cell phones, key fobs, garage door openers, most GPS receivers, many radar systems and more.”
Inside a smartphone, SAWs function as precise filters. Radios in the phone receive signals from a cell tower and convert them into tiny mechanical vibrations. These vibrations allow chips to remove unwanted signals and noise, after which the cleaned signal is converted back into radio waves for communication.
A phonon laser replaces complex hardware
In the current study, Eichenfield and his team developed a new way of making SAWs using a “phonon laser.” It works like a run-of-the-mill laser pointer, except that it generates vibrations.
“Think of it almost like the waves from an earthquake, only on the surface of a small chip,” said Alexander Wendt, a graduate student at the University of Arizona and lead author of the new study.
Most SAWs devices today require two different chips and a power source to generate these waves. The team’s device, in contrast, works using just a single chip and can potentially produce SAWs at much higher frequencies paired only with a battery.
Rebuilding the laser for vibrations
To understand how the team’s new SAW device works, it helps to think about a traditional laser.
Most lasers around today, known as “diode lasers,” work by bouncing a beam of light between two microscopic mirrors on the surface of a semiconductor chip. As that light bounces back and forth, it bangs into atoms in the semiconductor material that have an electric field running through them from a battery or other power source. In the process, those atoms eject even more light, and the beam becomes more powerful.
“Diode lasers are the cornerstone of most optical technologies because they can be operated with just a battery or simple voltage source, rather than needing more light to create the laser like a lot of previous kinds of lasers,” Eichenfield said. “We wanted to make an analog of that kind of laser but for SAWs.”
To do that, the team developed a device that’s shaped like a bar and measures about half a millimeter from end to end.
The device is a stack of materials: In its finished form, it’s made from a wafer of silicon, the same material in most computer chips. On top of that is a thin layer of a material called lithium niobate. Lithium niobate is a “piezoelectric” material, which means that when it vibrates, it also produces oscillating electric fields. Equivalently, when oscillating electric fields are present, they create vibrations.
Last, the device includes an even thinner layer of indium gallium arsenide—an unusual material that, when hit with a weak electric field, can accelerate electrons to incredibly fast speeds.
Altogether, the team’s stack allows vibrations on the surface of the lithium niobate to directly interact with electrons in the indium gallium arsenide.
Amplifying waves on a chip
The device works a bit like a wave pool.
When the researchers pump their device with an electric current in the indium gallium arsenide, waves will form in the thin layer of lithium niobate. Those waves slosh forward, hit a reflector, then slosh back—similar to light bouncing between two mirrors in a laser. Every time those waves move forward, they get stronger. Every time they move backward, they get a little weaker.
“It loses almost 99% of its power when it’s moving backward, so we designed it to get a substantial amount of gain moving forward to beat that,” Wendt said.
After several bounces, the wave becomes very large. The device lets a little of that wave leak out one side, which is equivalent to how laser light builds up and leaks out from between its mirrors.
The group was able to generate SAWs that rippled at a rate of about 1 gigahertz, or billions of times per second. But the researchers also think they can easily increase that to frequencies in the many tens of gigahertz or even hundreds of gigahertz.
That’s much higher frequency than traditional SAW devices which tend to top out at about 4 gigahertz.
Toward single chip radios
Eichenfield says the new device could lead to smaller, higher performance, and lower power wireless devices like cell phones.
In a smartphone, for example, numerous different chips convert radio waves into SAWs and back again multiple times every time you send a text, make a call, or access the internet.
His team wants to streamline that process, designing single chips that can do all that processing using SAWs alone.
“This phonon laser was the last domino standing that we needed to knock down,” Eichenfield said. “Now we can literally make every component that you need for a radio on one chip using the same kind of technology.”
Reference: “An electrically injected solid-state surface acoustic wave phonon laser” by Alexander Wendt, Matthew J. Storey, Michael Miller, Dalton Anderson, Eric Chatterjee, William Horrocks, Brandon Smith, Ping-Show Wong, Shawn Arterburn, Thomas A. Friedmann, Lisa Hackett and Matt Eichenfield, 14 January 2026, Nature.
DOI: 10.1038/s41586-025-09950-8
This work is supported by the Laboratory Directed Research and Development program at Sandia National Laboratories.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
1 Comment
Up next, physically DRM by cracking the chips of people that don’t pay a subscription to anything that has a chip in it. Deadman switches for not ‘checking in’ to a company, and end of all their hardware when they go offline (bankrupt) or want to force updates. Current e-waste says hold my beer.