Graphene’s Accordion Effect Boosts Wearable Tech Future

It was only about two decades ago that graphene was discovered. In such a short period, this “miracle material” has become integral to electronics and semiconductor technology, energy storage, thermal management, materials science, and other industries. 

Ever since Professors Kostya Novoselov and Andre Geim from the University of Manchester isolated and characterized graphene in 2004, for which they received the 2010 Nobel Prize in Physics, the material has remained one of the most exciting research fields in electronics.

Graphene is a two-dimensional (2D) material consisting of an extremely thin sheet of just a single layer of carbon atoms. It exhibits remarkable properties, including its lightweight, very high electrical conductivity, and strong mechanical strength.

Now, researchers have discovered a new property of graphene using a unique method.

The Accordion Effect: Making Graphene Very Stretchable 

Led by Jani Kotakoski, the team of physicists at the University of Vienna has made graphene, for the first time, substantially more stretchable by playing it just like an accordion. This new property was revealed by a clean and airless measurement environment.

The ripples in graphene make it stretchable, paving the way for its use in wearables, where materials need to bend and move with the body while still working reliably.

Published in the journal Physical Review Letters¹, the study was conducted in collaboration with the Vienna University of Technology and was funded by the Austrian Science Fund (FWF).

The team of researchers carried out experiments that actually clarified that graphene’s extreme stiffness is because of the atoms in the material arranged in a honeycomb shape; as such, removing some of the atoms alongside their bonds reduces their stiffness. 

Scientific studies have actually reported contradictions; both a slight reduction and a significant increase.

The latest study made this very clear thanks to using advanced devices, which shared the same clean and airless setting. According to Katokoshi:

“This unique system we have developed in the University of Vienna allows us to examine 2D materials without interference.” 

The clean, airless environment allows samples to be transported between the different devices without exposing them to ambient air.

“For the first time this kind of experiment has been carried out with the graphene fully isolated from ambient air and the foreign particles it contains. Without this separation, these particles would quickly settle on the surface affecting the experiment procedure and measurements.”

– The study’s first author, Wael Joudi

This focus on the cleanliness of the material surface actually resulted in the revelation of the accordion effect in association with the stiffness of graphene.

Removing two neighbouring atoms already causes a noticeable bulging of the initially flat material. Several of these bulges together lead to a corrugation of the material.

“You can imagine it like an accordion. When pulled apart, the waved material now gets flattened, which requires much less force than stretching the flat material and therefore it becomes more stretchable.” 

– Joudi

The formation of waves and the subsequent stretchability have been confirmed by the simulations conducted by Florian Libisch and Rika Saskia Windisch, theoretical physicists from the Vienna University of Technology.

The study reported observing the substance’s resistance to being deformed elastically decreasing from 286 to 158  N/m. The decrease is “significantly greater” than not only what is predicted by most studies but also in contrast to some measurements presented, which is because of corrugations produced by local strain at vacancies with at least two missing atoms.

The experiments carried out by the team further demonstrated “that the opposite effect can be measured when surface contamination is not removed before defect engineering.”

So, foreign particles on the material surface actually suppress this effect and even create an opposite result. In particular, the influence of these particles made graphene look even stiffer, which clarifies the contradictions that previous experiments have reported. According to Joudi:

“This shows the importance of the measurement environment when dealing with 2D materials. The results open up a way to regulate the stiffness of graphene and thus pave the way for potential applications.” 

Pushing Graphene’s Boundaries with Cutting-Edge Discoveries

Wearable technology is a booming industry, projected to grow past $150 billion before the decade is over.

A key component of wearable devices such as smart watches, rings, glasses, wrist bands, smart tattoos, jewelry, textiles, bandages, face masks, and a real-time glucose regulator is sensors, which facilitate the detection of biometrics, collect data, and then adapt to the body’s requirements.

The rapid development of flexible, perceptible electrical devices has led to graphene-based wearable sensors, which are notable for their great potential to make healthcare facilities more accessible and enhance the quality of sensing activities.

Unlike traditional semiconductors, which are rigid and have limited optoelectronic properties, and metals, which can be expensive, toxic, and experience degrading performance when subjected to mechanical stresses, graphene’s inherent properties make it highly suitable for building low-cost and multifunctional wearables.

The latest study has shown us the material’s amazing capability in these devices thanks to the dramatic increase in its stretchability. But that’s not the first time; over the years, many studies have investigated graphene’s role in wearables for various reasons and made many new discoveries about it.

Click here to learn why cleaning up graphene paves the way for its commercialization.

Graphene-based Wearable Strain Sensor 

Last year, researchers developed² a wearable strain sensor using graphene that can detect and broadcast silent speech.

The ‘smart’ choker built by researchers from the University of Cambridge captures micromovements in the throat, which are picked up by the strain sensor as an electrical signal and then fed into software models for processing and speech recognition. It can even pick up silently mouthed words and broadcast them.

The wearable has a distinct structure, featuring ordered thorough cracks on graphene-coated textiles, which significantly enhances sensitivity. The overlying structured graphene layer was applied to an integrated textile strain sensor.

The fabrication method for the technology is also simple, scalable, low-cost, and biocompatible. The device is adaptable to prolonged use and can withstand over 10,000 stretching-releasing cycles while maintaining stable and reliable electrical functionality.

By dynamically responding to throat micromovements, it can capture information-rich speech signals, which are processed through a neural network, with a record accuracy of 95.25% in speech decoding. 

The device, as per the researchers, has the potential to redefine the field of silent speech interface (SSI), which involves cutting-edge solutions to enable verbal communication without vocalisation.

Combining Graphene with Silk for Flexible Electronics

In another study, researchers at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) developed a uniform 2D layer of “fibroins” or fragments of silk protein on graphene. 

The usage of silk protein in designer electronics isn’t new, but it is limited due to silk fibers being a messy tangle of strands. Hence, the addition of graphene.

Silk-on-graphene could potentially create a much sought-after sensitive, tunable transistor  for health and wearable sensors. It can even serve as a crucial piece in “memristors” which are used in neural networks and allow computers to mimic the way the human brain functions.

Silk has been the subject of much research as a way of modulating electronic signals, but accomplishing control isn’t easy. So, the PNNL team carefully controlled the reaction conditions by precisely adding individual silk fibers to the water-based system that created a highly organized 2D layer of proteins packed in parallel β-sheets.

This is just the first step in controlled silk layering on functional electronic components, with future research to focus on improving the stability and conductivity of silk-integrated circuits.

A Graphene ‘Tattoo’ Implant to Treat Irregular Heartbeats

Meanwhile, researchers from the University of Texas at Austin (UT) and Northwestern University developed the first cardiac implant using graphene to treat cardiac arrhythmia.

Such disorders occur when the heart beats either too slowly or too quickly, and in many cases, this can lead to stroke, heart failure, and even sudden death. To treat arrhythmia, physicians usually use implantable pacemakers that detect irregular heartbeats and use electrical stimulation to correct the rhythm. 

These devices need hard, rigid materials that are not mechanically compatible with the body and are, therefore, difficult to affix to the heart’s surface. They may cause temporary discomfort, injure soft tissues, constrain natural motions, and induce complications.

Unlike these, the new biocompatible implant created is a graphene “tattoo”, which in appearance is similar to that of a temporary tattoo. It is thinner than a single strand of hair, but it works like a classical pacemaker.

The new thin device softly melds to the heart to both sense and treat irregular heartbeats. It is flexible enough to adapt to the delicate contours of the heart and strong enough to handle the dynamic motions of a beating heart.

“For bio-compatibility reasons, graphene is particularly attractive. Carbon is the basis of life, so it’s a safe material that is already used in different clinical applications. It also is flexible and soft, which works well as an interface between electronics and a soft, mechanically active organ.”

– Senior author Igor Efimov

To encase the graphene tattoo and have it adhere to the surface of a beating heart, the graphene was encapsulated within a silicone elastic membrane with a hole in it to access the graphene electrode. 10-micron-thick gold tape was then placed onto the encapsulating layer as a connection between the graphene and the external electronics used to measure and stimulate the heart.

The resulting total thickness of the device was about 100 micrometres, and it maintained stability for 60 days, comparable to the duration of temporary pacemakers.

To test the device, the researchers implanted it into a rat and found that it can successfully sense irregular heart rhythms and then provide electrical stimulation via a series of pulses without affecting the heart’s natural motions. 

Notably, the technology is optically transparent, which means researchers can use an external source of optical light to record and stimulate the heart through the device. This offers a novel approach to identifying and treating heart-related diseases and creates new opportunities for optogenetics.

Even Imperfect Graphene Has Big Benefits

Less than two years ago, researchers from the Vienna University of Technology actually developed a computer model of realistic graphene structures, which showed that graphene’s excellent electronic properties are very stable. This means that even not-so-perfect graphene pieces can be used for technological applications.

So, the electric current propagation of graphene is calculated on an atomic scale in a really small piece of it. Professor Florian Libisch from the Institute of Theoretical Physics at TU Wien explained at the time that electrons have several different ways to move through the material, and not only that, but they can take several paths at the same time, which can overlap in different ways.

The paths cancel each other out at very specific energy values, at which the probability of electrons passing through the piece of graphene is extremely low and the electric current is minimal, which is called “destructive interference.”

The dramatic decrease in current flow at very specific energy values is “a highly desirable effect technologically,” which can be used to process information on a tiny scale, much like electronic components do in computer chips, and for the development of novel quantum sensors.

It is not so simple, though, as the graphene piece’s size and shape aren’t always the same. Other factors like unwanted atoms, atoms being wobbly, and there being many interactions between several electrons, which are very difficult to calculate, need to be taken into account to “describe the material graphene in a truly realistic way.”

So, the researchers combined their years of experience in accurately describing different effects in materials in computer models to develop a comprehensive model that includes all relevant error sources and perturbation effects that exist in graphs. This enabled them to show that the desired effects are visible even when there are error sources. 

The study has been an important one in demonstrating the potential of using quantum effects in graphene in a controlled way.

Turning Graphene Into Tiny Magnets

Amidst all this, German experts added yet another aspect to graphene’s diverse properties that showed the material’s potential in magnetic switches and storage devices.

Researchers from the University of Duisburg-Essen (UDE) conducted experiments at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), where they fired short terahertz (THz) pulses at tiny discs of the material, which very briefly turned them into very strong magnets. This discovery may prove useful for developing future magnetic switches and storage devices.

So, what the scientists did here was they used existing semiconductor methods to put thousands of graphene discs the size of micrometers (μm) on a small chip, which was then subjected to short terahertz pulses, the radiation type that falls between the microwave and infrared range.

For the light source, they used a FELBE free-electron laser at the HZDR that can produce ultra-intense terahertz pulses.

Besides micrometer-sized discs of graphene turning into electromagnets, the team even generated magnetic fields in the range of 0.5 Tesla, about 10,000 times the magnetic field of the Earth, which only lasted ten picoseconds or one-hundredth of a billionth.

To achieve this success, however, the researchers had to polarize the terahertz flashes in a particular way. Here, specialized optics altered the direction of radiation’s oscillation so that it moved helically through space.

When the circularly polarized flashes strike the tiny discs, free electrons in them start to circle, which basically turns the discs into tiny electromagnets.

The simple and highly efficient process, according to the researchers, could be used for scientific experiments to have a more detailed understanding of material properties. Notably, the magnetic field remained unipolar, which makes it beneficial for certain experiments.

In the future, these tiny magnets may even find application in magnetic storage technology and spintronics.

Investing in Graphene

One company that stands out in the graphene sector is CVD Equipment Corporation (CVV +2.11%). The company designs and manufactures systems used in chemical vapor deposition, a key technique for producing high-quality graphene. And as industries continue to explore real-world applications for graphene, especially in electronics and materials science, CVD’s niche focus may give it a strategic advantage as demand scales.

CVD Equipment Corporation (CVV +2.11%)

The US-based CVD Equipment develops chemical vapor deposition (CVD) systems, which are utilized to create advanced materials such as graphene, as well as coatings used in energy, aerospace, and other industries.

It also offers graphene R&D and specialized production equipment to produce high-quality graphene at scale.

The company operates through two segments. The first is CVD Equipment, which designs and manufactures physical vapor transport, chemical vapor deposition, and thermal process equipment. The second is Stainless Design Concepts (SDC), whose focus is on ultra-high purity gas and chemical delivery control systems.

When it comes to CVD stock’s market performance, as of writing, it is trading at $2.84, down 34% YTD. With that, it has achieved a market capitalization of $20 million while having an EPS (TTM) of -0.28 and a P/E (TTM) of -10.43.

As for company financials, CVD reported revenue of $26.9 million for the full year of 2024, an 11.5% YoY increase. This was primarily driven by an increase in revenues from aerospace contracts in progress, the SDC segment, and the $0.8 million of final sales by the MesoScribe segment, which closed its operations last year.

CVD Equipment’s gross profit margin percentage jumped by 2.6% to 23.6% in 2024. The operating loss for the period was $2.4 million, and the net loss was $1.9 million, or $0.28 per basic and diluted share.

Last year, the company also saw an 8.9% increase in bookings of new orders, which reached $28.1 million, while the backlog at the end of the year was $19.4 million.

“During 2024 we continue to see an ongoing recovery of our aerospace and defense market,” said CEO Manny Lakios while noting that the silicon carbide market remains “challenging due to overcapacity and the global decline in wafer prices.”

Latest on CVD Equipment Corporation

Conclusion

Known for being light, flexible, tough, and having high electrical conductivity, graphene has been extensively researched and utilized for applications in the energy, electronics, and health sectors.

As we noted above, several exciting developments, like silent speech chokers and heart-monitoring tattoos, are constantly expanding the world of graphene. Now, the latest discovery of the accordion effect in graphene is adding yet another property to it: enhanced stretchability, which shows the magic material’s compatibility with wearables.

Combined with its superior electrical, mechanical, and biocompatible properties, graphene is a highly promising material for powering next-generation smart wearables!

Click here to learn how graphene will play a crucial role in 6G internet.

Studies Referenced:

1. Joudi, W., Windisch, R. S., Trentino, A., Propst, D., Madsen, J., Susi, T., Mangler, C., Mustonen, K., Libisch, F., & Kotakoski, J. (2025). Corrugation-dominated mechanical softening of defect-engineered graphene. Physical Review Letters, 134(16), 166102. https://doi.org/10.1103/PhysRevLett.134.166102

2. Tang, C., Xu, M., Yi, W., Zhang, Y., Wang, J., Li, H., & Zhao, Y. (2024). Ultrasensitive textile strain sensors redefine wearable silent speech interfaces with high machine learning efficiency. NPJ Flexible Electronics, 8, 27. https://doi.org/10.1038/s41528-024-00315-1