Signal transmission by sound surpasses electronic circuits

Nanotechnology

Technological Innovation Website Editorial Team - July 10, 2025

Acoustic technology has broad reach when it comes to the chip dimension and down. [Image: Xiang Xi et al. - 10.1038/s41586-025-09092-x]

Acoustic technology

When a percussionist hits a drum, they vibrate the drumhead, and this vibration contains a signal that we can decode as music. When the drum stops vibrating, the music ends—or, in physical terms, we lose the signal.

But we can also use very small drums for other things, such as a mechanical qubit for quantum computers , a resonator that displays quantum phenomena on a macroscale , or, more generally, to store digital data in the vibrations of a quantum drum .

It was in these more advanced applications that Xiang Xi and colleagues at the University of Copenhagen in Denmark have now innovated, creating an ultra-thin drumhead, about 10 mm wide. And it's not even smooth—it's perforated with a multitude of triangular holes.

The result is impressive: The drum made with this membrane allows vibrations to travel throughout the entire vibrating membrane with almost no loss. In fact, there is so little loss that this drum is far better at transmitting information than the signal processing performed by the best electronic circuits available.

Magnification of the membrane, made of silicon nitride. The colors represent out-of-plane motion—red means part of the membrane moves upward, and blue means part of it moves downward. [Image: Albert Schliesser/Xiang Xi]

Mechanical transmission of signals

To use the drum to transmit information, essentially a mechanical transmission of data, the signal consists of phonons , quasiparticles that can be thought of as vibrations in a solid material. The atoms vibrate and jostle against each other, so to speak, carrying a given signal through the material—and this is where signal loss comes into play.

If the signal loses strength, or parts of the signal are lost in the form of heat or incorrect vibrations, it ends up not being possible to decode it correctly, which makes it difficult to create acoustic components and even acoustic computing , an alternative form of computing that promises to solve electronically incomputable problems - today there is even talk of phononics , a type of electronics that works with phonons, instead of electrons.

In this case, loss is measured as a decrease in the amplitude of the sound wave as it moves through the membrane. What the team discovered is that a membrane filled with very precise holes—triangular holes—is much better at transporting vibrations than a smooth membrane.

When the researchers routed the signal through their perforated membrane—and around the holes, where the signal changes direction—the loss is about one phonon in a million. For comparison, the amplitude of current fluctuations in a similar electronic circuit decreases about a hundred thousand times faster.

You can do a lot of things with sound waves inside chips, including real earthquakes on a chip . [Image: Govert Neijts et al. - 10.1063/5.0220496]

Multiple uses

The team wasn't working on a specific application, but the possibilities of this breakthrough are broad. Quantum computers, for example, rely on the super-precise transfer of signals between their different components, and acoustic transfer is among the various mechanisms being investigated.

Another field of application is sensors that, for example, can measure the smallest biological fluctuations in our own bodies, where signal transmission is also crucial. But even basic research will be interested in the membrane, for example, to test Heisenberg uncertainty .

"Right now, we want to experiment with the method to see what we can do with it. For example, we want to build more complex structures and see how we can make phonons move around them, or build structures where we can make phonons collide like cars at an intersection. This will give us a better understanding of what is ultimately possible and what the new applications are," said Professor Albert Schliesser, whose team enjoys pushing the boundaries in measurements .

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