Listening to ultrasonic signals reveals the mechanical behavior of next-generation batteries

Simón Montoya-Bedoya – simonmontoyabedoya@gmail.com
Bluesky: @simontoyabe.bsky.social
Instagram: @simontoyabe
Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas, 78712-1591, United States

Prof. Michael R. Haberman (Walker Department of Mechanical Engineering, The University of Texas at Austin)

Other contributors to the research:
Donal P. Finegan (National Laboratory of the Rockies, Golden, CO, US)
Hadi Khani (Texas Materials Institute, The University of Texas at Austin)
Ofodike Ezekoye (Walker Mechanical Engineering Department, The University of Texas at Austin)

Popular version of 2aPAb4 – Non-destructive ultrasonic monitoring of next-generation lithium-ion batteries
Presented at the 189th ASA Meeting
Read the abstract at https://eppro02.ativ.me/appinfo.php?page=Session&project=ASAASJ25&id=3977608&server=eppro02.ativ.me

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Have you noticed how heavily our current society depends on batteries? Batteries are used everywhere, from powering your phone to electrifying mobility, and energy storage to mitigate the intermittent nature of renewable energy sources like wind and sun. This increased demand for lithium-ion batteries (LIBs) has led to the exploration of new technologies with improved attributes such as safer operation or improved lifetime. For example, silicon solid-state batteries (Si-SSB) are promising because silicon as an anode material offers a higher specific capacity (~3500 mAh/g) than graphite (~300 mAh/g) used in conventional LIBs. They are also potentially safer to operate due to the use of a solid electrolyte rather than the flammable liquid electrolyte used in conventional LIBs.

However, Si-SSBs come with their own challenges associated with the avoidance of a liquid electrolyte, primarily the requirement to maintain reliable interfacial contact between all the solid layers for lithium-ion movement. Si-SSBs are therefore more brittle and more prone to contact loss and fracture.

Another challenge in studying the intricate mechanical changes that arise from the electrochemical processes in the battery is that we are “blind” to them, in other words, we cannot see inside batteries while they are operating. That’s why, just as a doctor uses ultrasound to monitor a beating heart, we can use ultrasonic waves to monitor batteries without opening them, as represented by the cartoon in Fig. 1. The key to understanding what changes within the batteries is having information about how the movement of lithium ions alters its mechanical properties. When lithium ions migrate during charging and discharging, they cause swelling, internal stresses, and sometimes fracture within the battery structure. These mechanical changes can significantly affect the propagation of ultrasonic waves through the material. This is specifically true for the silicon anode, where silicon forms alloys with the lithium ions, rather than the lithium ions becoming embedded in the molecular structure as occurs in conventional batteries. These electrochemical changes lead to large volumetric and mechanical changes. Thus, SSBs are a compelling technology to explore using ultrasound using ultrasonic signals observables, such as shifts in the time of flight (TOF) of the wave through the battery, or changes in how sound is absorbed or scattered. These “acoustic fingerprints” can potentially help us gain more insights into degradation in these next-generation (“next-gen”) batteries and therefore improve the technology for more widespread use in commercial products.

Figure 1. Analogy of the usage of ultrasonic waves for battery diagnostics, similar to how a doctor would use ultrasonics to monitor heart health. [Image generated with AI using Google NanoBanana Pro]

We aim to extend the use of ultrasonic testing methods for next-gen batteries and investigate opportunities and challenges associated with evaluating this new technology. In this work, we investigated both contact-based and immersion ultrasonic testing to monitor changes in the mechanical properties of Si-SSBs under cycle-induced aging.

In general, our experiments showed an overall stiffness reduction with aging as indicated by the increase in ultrasonic wave TOF (see Fig 2a). Further, we observed an overall reduction of transmitted energy with increased cycling. These two findings may be associated with the accumulation of damage at layer interfaces associated with the creation of solid-gas interfaces and/or debonding between layers. Finally, ultrasonic imaging using immersion testing provided information regarding the distribution and evolution of damage in space as these next-gen batteries are aged (see Fig 2b).

By refining these techniques to evaluate next-gen battery technologies, we will develop more sensitive methods to determine when something is wrong before it’s too late. In a world increasingly dependent on safe and reliable energy storage, the ability to “listen” to batteries might be precisely what we need to power the clean energy revolution.

Figure 2. Evolution of cell stiffness during aging. a) Stiffness of the SSB, normalized to its initial value, plotted against discharge capacity for both charged (blue) and discharged (red) states. With representative ultrasonic images from transmitted signals at two states of the SSB: b.1) pristine before cycling, and b.2) after 40 cycles of aging. We observed a significant reduction in transmission in the middle region of the SSB. Warmer colors indicate higher transmission, and dashed outlines mark the active cell region.

Using Smartphones To Improve Disaster Search and Rescue

In disaster situations where visibility is limited, sound that can penetrate through rubble is the key to finding trapped victims quickly. #ASA_ASJ2025 #ASA189

HONOLULU, Dec. 5, 2025 — When a natural disaster strikes, time is of the essence if people are trapped under rubble. Conventional methods use radar-based detection or employ acoustics that rely on sounds made by victims.

Since most people carry their phones with them every day, Shogo Takada, a student at the University of Tokyo, is working on a way to use smartphone microphones to assist in locating disaster victims.

Takada will present his results Friday, Dec. 5, at 11:45 a.m. HST as part of the Sixth Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan, running Dec. 1-5 in Honolulu, Hawaii.

A diagram showing a hypothetical search and rescue situation utilizing a smartphone microphone. Credit: Shogo Takada

A diagram showing a hypothetical search and rescue situation utilizing a smartphone microphone. Credit: Shogo Takada

“This method is effective for locating victims buried under debris or soil caused by earthquakes or landslides because sound waves can propagate through them,” said Takada. “It could also be used to locate rescuers affected by secondary disasters.”

The method combines two types of sound sources, monopole and dipole. Radiating out equally in a circle, monopole sources create sound waves around the source, whereas dipole sources radiate sound from the front and back but cancel out on the sides. Dipole sound sources are directional, which can help researchers estimate the azimuth angle of the sound source, giving them information about the source’s location.

In a disaster situation, a rescuer would emit two dipole sounds, which would be received by the microphone of a trapped victim, and then an electromagnetic wave would be sent from the victim’s phone to broadcast their location. In the presence of sound-reflecting debris, a monopole sound can also be emitted by the rescuer to help reduce the effect of the debris. All of the sound sources can be incorporated into a formula to help estimate the location of the trapped person.

Takada’s technique proved highly successful in a field test on a disaster training site. The method achieved an error of 5.04 degrees away from the hypothetical victim, when searching over an area of 10 square meters.

“One limitation is that the method assumes the victim should possess a device equipped with a microphone,” said Takada. “This is a more restrictive condition compared to traditional techniques that detect sounds or voices emitted by the victim.”

However, given the widespread use of smartphones, Takada believes that this technique is promising and plans to refine it further.

“In future work, we plan to develop a method that can estimate not only the azimuth angle but also the elevation angle of the sound source,” Takada said. “Additionally, we aim to expand the system to use two sound sources to achieve three-dimensional localization.”

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——————— MORE MEETING INFORMATION ——————–

Main Meeting Website: https://acousticalsociety.org/honolulu-2025/
Technical Program: https://eppro02.ativ.me/web/planner.php?id=ASAASJ25

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting and/or press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE ACOUSTICAL SOCIETY OF JAPAN
ASJ publishes a monthly journal in Japanese, the Journal of the Acoustical Society of Japan as well as a bimonthly journal in English, Acoustical Science and Technology, which is available online at no cost https://www.jstage.jst.go.jp/browse/ast. These journals include technical papers and review papers. Special issues are occasionally organized and published. The Society also publishes textbooks and reference books to promote acoustics associated with various topics. See https://acoustics.jp/en/.

More Press Releases

Acoustic Suction Tweezers: A new compact acoustic gadget for small object manipulation

Shoya Yoneda – yoneda-shoya@ed.tmu.ac.jp

Department of Electrical Engineering and Computer Science
Tokyo Metropolitan University
Hino-shi, Tokyo, 191-0065
Japan

Kan Okubo – kanne@tmu.ac.jp

Popular version of 4pPA6 – Miniaturized Acoustic Suction Tweezers: Lift Control and Cap Design for Mobile Applications
Presented at the 189th ASA Meeting
Read the abstract at https://eppro02.ativ.me/appinfo.php?page=IntHtml&project=ASAASJ25&id=3983403&server=eppro02.ativ.me

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

Can you believe that ultrasound-induced forces can actually pull objects?
It may sound surprising, but this phenomenon is real. In this paper we introduce a fascinating world of sound-based manipulation.

Our research group has long been developing acoustic tweezers capable of picking up tiny objects using ultrasonic forces. (See https://youtu.be/PoZsKjst82g)

In our latest work, we take this idea a step further. By using a remarkably simple structure and cleverly harnessing the lifting force generated by sound, we have created a new acoustic gadget: the acoustic suction tweezer.

Yes —acoustic suction tweezers, sometimes called an “acoustic pipette,” pull objects toward them using sound energy, with no vacuum effect involved.

Proposal Device: Acoustic Suction Tweezer

Video 1. Introduction of the Acoustic Suction Tweezer

Sound exerts a force on objects known as the acoustic radiation force, which typically pushes objects away. However, by placing a small aperture unit in front of the transducer, we can shape a unique sound field that transforms this force into attraction and lift —almost like a miniature vacuum cleaner made of sound. To harness this effect, we developed an acoustic focusing cap through extensive trial and error, testing various designs manufactured with a 3D printer to evaluate their performance.

Figure 1. Make various Acoustic Focusing Caps

Figure 1. Make various Acoustic Focusing Caps

The figure below shows the simulated sound pressure levels. Relatively high-pressure regions are concentrated near the tip of the cap, which correlates with the generation of attractive acoustic radiation forces in this area.

Figure 3. An Example of Sound Pressure Levels Inside the Cap

Figure 2. An Example of Sound Pressure Levels Inside the Cap

How does it compare to other devices?
Our previously proposed acoustic tweezers require large transducer arrays and complex phase control (See https://www.eurekalert.org/news-releases/923462). In contrast, the acoustic suction tweezers overcome these limitations through careful design considerations. Remarkably, they lift objects even larger than the wavelength of sound, such as 15 mm polystyrene spheres.

Video 2. Lifting a 15mm sphere

Practicality
The Acoustic Suction Tweezer excels in practicality; it can be implemented quickly, at low cost, using just a 3D printer and a single ultrasonic transducer.

We confirmed that the device can handle lightweight industrial items such as coated wires and even delicate objects like feathers —materials conventional vacuum tweezers struggle to grasp.

Video 3. Lifting a coated wire

We confirmed that the device can handle lightweight industrial items such as coated wires and even delicate objects like feathers —materials conventional vacuum tweezers struggle to grasp.We expect this device to have strong potential for applications in diverse fields, including medicine, biochemistry, and engineering. We also hope that this system will inspire further innovation and the creation of many other useful acoustic-based tools.

Remotely Moving Objects Underwater Using Sound #ASA188

Remotely Moving Objects Underwater Using Sound #ASA188

Acoustic metamaterial enables pushing, rotating, and more complex movements in 3D.

Media Contact:
AIP Media
301-209-3090
media@aip.org

NEW ORLEANS, May 20, 2025 – Sound can do more than just provide a nice beat. Sound waves have been used for everything from mapping the seafloor to breaking apart kidney stones. Thanks to a unique material structure, researchers can now move and position objects underwater without ever touching them directly.

Dajun Zhang, a doctoral student at the University of Wisconsin-Madison, will present his work on developing a metamaterial for underwater acoustic manipulation Tuesday, May 20, at 3:20 p.m. CT as part of the joint 188th Meeting of the Acoustical Society of America and 25th International Congress on Acoustics, running May 18-23.

metamaterial

The metamaterial created by Zhang is used to push and rotate an object adorned with the University of Wisconsin’s Bucky the Badger. Credit: Dajun Zhang

A metamaterial is a composite material that exhibits unique properties due to its structure. Zhang’s metamaterial features a small sawtooth pattern on its surface, which allows adjacent speakers to exert different forces on the material based on how the sound waves reflect off it. By carefully targeting the floating or submerged metamaterial with precise sound waves, Zhang can push and rotate any object attached to it exactly as much as he wants.

Manipulating objects in water without touching them could make a lot of underwater work easier. It could also be used inside the human body, which is mostly water, for applications like remote surgery or drug delivery.

“Our metamaterial offers a method to apply different acoustic radiation forces on objects in liquid media, such as underwater robots and vehicles, parts for assembly, or medical devices and drugs,” said Zhang.

However, manufacturing underwater metamaterials with the correct properties for object manipulation is difficult, especially with conventional methods.

“Current fabrication methods for underwater metamaterials do not provide the resolution or material properties required and are usually very expensive,” said Zhang. “To solve this issue, I developed a new fabrication method. This method is not only low cost and easy to implement but also achieves high fabrication resolution and large acoustic impedance contrast with water, which are keys to underwater metamaterials.”

In tests, Zhang used his metamaterial to manipulate floating objects, such as wood, wax, and plastic foam, along with objects completely submerged underwater. He attached his metamaterial to each object and used acoustic waves to push, pull, and rotate them. With submerged objects, this technique gave him the ability to manipulate them in three dimensions.

Zhang plans to continue his work, developing a metamaterial patch that is smaller and more flexible. He hopes his work will lead to new uses in medicine and underwater robotics.

“Our research opens new opportunities for both underwater acoustic metamaterials and remote manipulation,” said Zhang. “Acoustic metamaterials and metasurfaces can now be used to generate forces remotely for underwater or in-body levitation, actuation, and manipulation applications.”

——————— MORE MEETING INFORMATION ———————
Main Meeting Website: https://acousticalsociety.org/new-orleans-2025/
Technical Program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAICA25

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the meeting and/or press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

ABOUT THE INTERNATIONAL COMMISSION FOR ACOUSTICS
The purpose of the International Commission for Acoustics (ICA) is to promote international development and collaboration in all fields of acoustics including research, development, education, and standardization. ICA’s mission is to be the reference point for the acoustic community, becoming more inclusive and proactive in our global outreach, increasing coordination and support for the growing international interest and activity in acoustics. Learn more at https://www.icacommission.org/.

From Traditional to Technological: Advancements in Fresco Conservation #ASA187

From Traditional to Technological: Advancements in Fresco Conservation #ASA187

Laser Doppler vibrometry is being used to conserve frescos in the US Capitol building

Media Contact:
AIP Media
301-209-3090
media@aip.org

MELVILLE, N.Y., Nov. 21, 2024 – Fresco painting, a technique that dates back to antiquity, involves applying dry pigments to wet plaster, creating stunning artwork that can last for centuries. Over time, however, these masterpieces often face degradation due to delamination, where decorative plaster layers separate from the underlying masonry or structural plaster. This deterioration can compromise the structural integrity of the artwork, necessitating restoration efforts.

Historically, conservators have gently knocked on the plaster with their knuckles or small mallets to assess the condition of the fresco. By listening to the emitted sound, they could identify the delaminated areas needing repair. While effective, this technique is limited both by the conservator’s experience and the small number of people in the world who possess these skills. 

Detection color map of a fresco in the U.S. Capitol. Brighter colors indicate more vibration in the plaster, and therefore, a delamination. Credit: Nick Gangemi

Recent research by Joseph Vignola at the Catholic University of America is revolutionizing fresco assessment. Vignola and his team have applied laser Doppler vibrometry to locate delamination in the frescos of Constantino Brumidi in the U.S. Capitol building. This innovative method uses a laser to measure the vibration of a surface, enabling the team to detect delaminated areas based on their unique vibrational characteristics.

“By transmitting sound waves to induce motion in the plaster, the system captures vibrational signatures that reveal detailed information about the structural condition of the artwork,” said researcher Nicholas Gangemi.

One of the remarkable aspects of this technology is its ability to identify regions of delamination that may not exhibit any obvious outward signs of damage. The group’s current research focuses on developing techniques to accurately resolve the size and shape of these hidden defects, facilitating precise repairs that will ensure the preservation of the artwork for future generations.

Moreover, advancements in signal processing are enhancing the ability to analyze complex shapes of delaminated regions. 

Gangemi will present research related to this work Thursday, Nov. 21, at 11:25 a.m. ET as part of the virtual 187th Meeting of the Acoustical Society of America, running Nov. 18-22, 2024.

This research explores the simulation of frescoes with known delaminated shapes to validate their methods, ensuring that they can accurately assess and restore the artworks. These fresco surrogates have also offered a platform for Vignola and his team to scientifically validate the dated technique of knocking on a fresco and listening to the sound it makes. 

Looking ahead, this research aims to democratize conservation expertise by creating simple, accessible tools. One possibility is to develop smartphone or computer apps that utilize straightforward algorithms, allowing anyone—regardless of their background—to engage with fresco conservation. This initiative not only enhances the preservation process but also raises awareness of the challenges and techniques involved in maintaining these cultural treasures.

As technology continues to bridge the gap between traditional methods and modern science, fresco conservation is poised for a transformative future.

“We are developing techniques to allow us to preserve the artwork for generations to come,” Gangemi said.

———————– MORE MEETING INFORMATION ———————–
​Main Meeting Website: https://acousticalsociety.org/asa-virtual-fall-2024/
Technical Program: https://eppro01.ativ.me/src/EventPilot/php/express/web/planner.php?id=ASAFALL24

ASA PRESS ROOM
In the coming weeks, ASA’s Press Room will be updated with newsworthy stories and the press conference schedule at https://acoustics.org/asa-press-room/.

LAY LANGUAGE PAPERS
ASA will also share dozens of lay language papers about topics covered at the conference. Lay language papers are summaries (300-500 words) of presentations written by scientists for a general audience. They will be accompanied by photos, audio, and video. Learn more at https://acoustics.org/lay-language-papers/.

PRESS REGISTRATION
ASA will grant free registration to credentialed and professional freelance journalists. If you are a reporter and would like to attend the virtual meeting and/or press conferences, contact AIP Media Services at media@aip.org. For urgent requests, AIP staff can also help with setting up interviews and obtaining images, sound clips, or background information.

ABOUT THE ACOUSTICAL SOCIETY OF AMERICA
The Acoustical Society of America is the premier international scientific society in acoustics devoted to the science and technology of sound. Its 7,000 members worldwide represent a broad spectrum of the study of acoustics. ASA publications include The Journal of the Acoustical Society of America (the world’s leading journal on acoustics), JASA Express Letters, Proceedings of Meetings on Acoustics, Acoustics Today magazine, books, and standards on acoustics. The society also holds two major scientific meetings each year. See https://acousticalsociety.org/.

Mitigating Train Derailments Through Proactive Condition Monitoring of Rolling Stock

Constantine Tarawneh – constantine.tarawneh@utrgv.edu

University Transportation Center for Railway Safety
University of Texas Rio Grande Valley
Edinburg, Texas, 78539
United States

Popular version of 3aPA4 – Preventing Hot Bearing Derailments via Wireless Onboard Condition Monitoring
Presented at the 187th ASA Meeting
Read the abstract at https://doi.org/10.1121/10.0035227

–The research described in this Acoustics Lay Language Paper may not have yet been peer reviewed–

The 2023 train derailment that occurred in East Palestine, OH, brought attention to the limitations of the detectors currently used in the industry. Typically, the health of train bearings is monitored intermittently through wayside temperature detection systems that can be as far as 40 miles apart. Nonetheless, catastrophic bearing failure is often sudden and develops rapidly. Current wayside detection systems are reactive in nature and depend on significant temperature increases above ambient. Thus, when these systems are triggered, train operators rarely have enough time to react before a derailment occurs, as it did in East Palestine, OH. Multiple comprehensive studies have shown that the temperature difference between healthy and faulty bearings is not statistically meaningful until the onset of catastrophic failure. Thus, temperature alone is an insufficient metric for health monitoring.

Video 1. Vibration and noise emitted from train bearings.

Over the past two decades, we have demonstrated vibration-based solutions for wireless onboard condition monitoring of train components to address this problem. Early stages of bearing failure are reliably detected via vibrations and acoustics signatures, as shown in Video 1, which can also be used to determine the severity and location of failure. This is accomplished in three levels of analysis where Level 1 determines the bearing condition based on the vibration levels within the bearing as compared to a maximum vibration threshold for healthy bearings. In Level 2, the vibration signature is analyzed to identify the defective component within the bearing, and Level 3 estimates the size of the defect based on a developed correlation that relates the vibration levels to defect size.

To demonstrate this process, Figure 1 provides the vibration and temperature profiles for two bearings. Examining the vibration profile, the vibration levels within bearing R7 exceed the maximum threshold for healthy bearings 730 hours into the test, thus indicating a defective bearing. At the same time, the operating temperature of that bearing never exceeded the normal operating range, which would suggest that the bearing is healthy. Upon teardown and visual inspection, we found severe damage to the bearing components at the raceways, as pictured in Figure 2. Despite severe damage all around the bearing inner ring (cone), the operating temperature did not indicate any abnormal behavior.

Figure 1: Vibration and temperature profiles of two railroad bearings showcasing how vibration levels within the bearings can indicate the development of defects while operating temperature does not exhibit any abnormal behavior.
Figure 2: Picture of the damage that developed within bearing R7 (refer to Figure 1). Interestingly, the bearing inner ring (cone) had severe damage and a crack that the vibration levels picked up but not the operating temperature.

We believe that vibration-based sensors can provide proactive monitoring of bearing conditions affording rail operators ample time to detect the onset of bearing failure and schedule non-disruptive maintenance. Our work aims to continue to optimize these new methods and help the rail industry deploy these technologies to advance rail safety and efficiency. Moreover, this research program has had an extraordinary transformative impact from the local to the national level by training hundreds of engineers from underrepresented backgrounds and positioning them for success in industry, government, and higher education.