Scientists Develop Acoustic "Tractor Beam" to Control Material Behavior

Researchers discover how sound waves can precisely manipulate tiny structural features called "kinks" to adjust a material's stiffness.

Mar. 22, 2026 at 8:49pm

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A team of researchers from UC San Diego, University of Michigan, and CNRS in France has shown that sound waves can be used to remotely alter how materials behave. By precisely controlling the movement of tiny structural features called "kinks" within a material, the researchers can adjust the material's stiffness in a step-by-step, predictable manner.

Why it matters

Controlling the location of kinks, which act as boundaries between different internal states within a material, has long been a challenge for materials scientists. Being able to precisely manipulate kinks using sound waves could enable the development of "adaptive" materials whose mechanical properties can be tuned on demand, with potential applications in fields like robotics and engineering.

The details

The researchers created a material model where shifting a kink requires no energy, an unusual property. In this model, the location of the kink determines the material's stiffness - the region around the kink is always soft, while stiffness increases progressively away from it. By sending targeted sound wave pulses, the researchers can move the kink in precise, incremental steps, effectively shifting which parts of the material are soft or stiff.

  • The study was published in Nature Communications on March 22, 2026.

The players

Nicholas Boechler

Co-corresponding author of the study and professor in the Department of Mechanical and Aerospace Engineering at the UC San Diego Jacobs School of Engineering.

UC San Diego

One of the institutions where the research was conducted.

University of Michigan

One of the institutions where the research was conducted.

CNRS

The French National Center for Scientific Research, one of the institutions where the research was conducted.

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What they’re saying

“Previous experiments showed that sound waves could move kinks, but the motion was often unpredictable and chaotic.”

— Nicholas Boechler, Co-corresponding author of the study

“Sending sound waves from one side pulls the kink toward the source. A small acoustic pulse nudges the kink slightly, and each subsequent pulse moves it further. In effect, we've developed a way to remotely control the material's internal state.”

— Nicholas Boechler, Co-corresponding author of the study

What’s next

The researchers plan to continue exploring how sound waves can be used to precisely control the behavior of materials, with potential applications in fields like robotics and engineering.

The takeaway

This breakthrough demonstrates that sound waves can be used to achieve unprecedented control over the internal structure of materials, opening up new possibilities for the development of "smart" or "adaptive" materials whose properties can be tuned on demand.