Aurelia Butler

Mobile phone batteries with a lifetime up to three times longer than today’s technology could be a reality thanks to an innovation led by engineers at RMIT University.
Rather than disposing of batteries after two or three years, we could have recyclable batteries that last for up to nine years, the team says, by using high-frequency sound waves to remove rust that inhibits battery performance.
Only 10% of used handheld batteries, including for mobile phones, are collected for recycling in Australia, which is low by international standards. The remaining 90% of batteries go to landfill or are disposed of incorrectly, which causes considerable damage to the environment.
The high cost of recycling lithium and other materials from batteries is a major barrier to these items being reused, but the team’s innovation could help to address this challenge.
The team are working with a nanomaterial called MXene, a class of materials that they say promises to be an exciting alternative to lithium for batteries in the future.
Leslie Yeo, Distinguished Professor of Chemical Engineering and lead senior researcher, said MXene was similar to graphene with high electrical conductivity.

“Unlike graphene, MXenes are highly tailorable and open up a whole range of possible technological applications in the future,” said Yeo from RMIT’s School of Engineering.
The big challenge with using MXene was that it rusted easily, thereby inhibiting electrical conductivity and rendering it unusable, he said.
“To overcome this challenge, we discovered that sound waves at a certain frequency remove rust from MXene, restoring it to close to its original state,” Yeo said.
The team’s innovation could one day help to revitalise MXene batteries every few years, extending their lifetime up to three times, he said.
“The ability to prolong the shelf life of MXene is critical to ensuring its potential to be used for commercially viable electronic parts,” Yeo said.

The research is published in Nature Communications.
How the innovation works
Co-lead author Mr Hossein Alijani, a PhD candidate, said the greatest challenge with using MXene was the rust that forms on its surface in a humid environment or when suspended in watery solutions.
“Surface oxide, which is rust, is difficult to remove especially on this material, which is much, much thinner than a human hair,” said Alijani from RMIT’s School of Engineering.
“Current methods used to reduce oxidation rely on the chemical coating of the material, which limits the use of the MXene in its native form.
“In this work, we show that exposing an oxidised MXene film to high-frequency vibrations for just a minute removes the rust on the film. This simple procedure allows its electrical and electrochemical performance to be recovered.”
The potential applications of the team’s work
The team says their work to remove rust from Mxene opens the door for the nanomaterial to be used in a wide range of applications in energy storage, sensors, wireless transmission and environmental remediation.
Associate Professor Amgad Rezk, one of the lead senior researchers, said the ability to quickly restore oxidised materials to an almost pristine state represented a gamechanger in terms of the circular economy.
“Materials used in electronics, including batteries, generally suffer deterioration after two or three years of use due to rust forming,” said Rezk from RMIT’s School of Engineering.
“With our method, we can potentially extend the lifetime of battery components by up to three times.”
Next steps
While the innovation is promising, the team needs to work with industry to integrate its acoustics device into existing manufacturing systems and processes.
The team is also exploring the use of their invention to remove oxide layers from other materials for applications in sensing and renewable energy.
“We are keen to collaborate with industry partners so that our method of rust removal can be scaled up,” Yeo said. More

The diagnosis of Parkinson’s disease has shaken many lives. More than 10 million people worldwide are living with it. There is no cure, but if symptoms are noticed early, the disease can be controlled. As Parkinson’s disease progresses, along with other symptoms speech changes.
Lithuanian researcher from Kaunas University of Technology (KTU), Rytis Maskeliūnas, together with colleagues from the Lithuanian University of Health Sciences (LSMU), tried to identify early symptoms of Parkinson’s disease using voice data.
Parkinson’s disease is usually associated with loss of motor function — hand tremors, muscle stiffness, or balance problems. According to Maskeliūnas, a researcher at KTU’s Department of Multimedia Engineering, as motor activity decreases, so does the function of the vocal cords, diaphragm, and lungs: “Changes in speech often occur even earlier than motor function disorders, which is why the altered speech might be the first sign of the disease.”
Expanding the AI language database
According to Professor Virgilijus Ulozas, at the Department of Ear, Nose, and Throat at the LSMU Faculty of Medicine, patients with early-stage of Parkinson’s disease, might speak in a quieter manner, which can also be monotonous, less expressive, slower, and more fragmented, and this is very difficult to notice by ear. As the disease progresses, hoarseness, stuttering, slurred pronunciation of words, and loss of pauses between words can become more apparent.
Taking these symptoms into account, a joint team of Lithuanian researchers has developed a system to detect the disease earlier.

“We are not creating a substitute for a routine examination of the patient — our method is designed to facilitate early diagnosis of the disease and to track the effectiveness of treatment,” says KTU researcher Maskeliūnas.
According to him, the link between Parkinson’s disease and speech abnormalities is not new to the world of digital signal analysis — it has been known and researched since the 1960s. However, as technology advances, it is becoming possible to extract more information from speech.
In their study, the researchers used artificial intelligence (AI) to analyse and assess speech signals, where calculations are done and diagnoses made in seconds rather than hours. This study is also unique — the results are tailored to the specifics of the Lithuanian language, in this way expanding the AI language database.
The algorithm will become a mobile app in the future
Speaking about the progress of the study, Kipras Pribuišis, lecturer at the Department of Ear, Nose, and Throat at the LSMU Faculty of Medicine, emphasises that it was only carried out on patients already diagnosed with Parkinson’s: “So far, our approach is able to distinguish Parkinson’s from healthy people using a speech sample. This algorithm is also more accurate than previously proposed.”
In a soundproof booth, a microphone was used to record the speech of healthy and Parkinson’s patients, and an artificial intelligence algorithm “learned” to perform signal processing by evaluating these recordings. The researchers highlight that the algorithm does not require powerful hardware and could be transferred to a mobile app in the future.
“Our results, which have already been published, have a very high scientific potential. Sure, there is still a long and challenging way to go before it can be applied in everyday clinical practice,” says Maskeliūnas.
According to the researcher, the next steps include increasing the number of patients to gather more data and determining whether the proposed algorithm is superior to alternative methods used for early diagnosis of Parkinson’s. In addition, it will be necessary to check whether the algorithm works well not only in laboratory-like environments but also in the doctor’s office or in the patient’s home. More

A research group has succeeded in measuring spin transport in a thin film of specific molecules — a material well-known in organic light emitting diodes — at room temperature. They found that this thin molecular film has a spin diffusion length of approximately 62 nm, a length that could have practical applications in developing spintronics technology. In addition, while electricity has been used to control spin transport in the past, the thin molecular film used in this study is photoconductive, allowing spin transport control using visible light.
Information processing devices — such as smartphones — are becoming more sophisticated because their information recording density constantly increases, thanks to advances in microfabrication technology. In recent years, however, the physical limits to processing are rapidly approaching, making further miniaturization difficult. Perhaps, though, the continued demand for more sophisticated technology requires a fundamental change in operating principles, so that faster, smaller, new devices can continue being made.
To meet this demand, a technology called spintronics — using the magnetic spin and the charge of electrons — is attracting attention as a key technology, that could unlock the next generation of advanced electronics. By aligning the direction of a magnetic spin and moving it like an electric current, it is possible to propagate information using very little power and generate less waste heat.
A research group, led by Professors Eiji Shikoh and Yoshio Teki of the Osaka Metropolitan University Graduate School of Engineering, has successfully measured spin transport, at room temperature, in a thin film of alpha-naphthyl diamine derivative (?NPD) molecules, a well-known material in organic light emitting diodes. This molecular thin film was found to have a spin diffusion length of approximately 62 nanometers, a distance that they expect can be used in practical applications.
To use spin transport to develop spintronics technology requires having a spin diffusion length in the tens of nanometer range at room temperature for accurate processing. The thin molecular film of ?NPD with a spin diffusion length of 62 nanometers — a long distance for molecular materials — was fabricated for this study by thermal evaporation in vacuum. While electricity has been used to control spin transport in the past, this new thin ?NPD molecular film is photoconductive, making it possible to control spin transport using visible light.
“For practical use, it will be necessary to uncover more details about spin injection and spin transport mechanisms through thin molecular films to control spin transport,” noted Professor Shikoh. “Further research is expected to lead to the realization of super energy-efficient devices that use small amounts of power and have little risk of overheating.” More

When two microscopic systems are entangled, their properties are linked to each other irrespective of the physical distance between the two. Manipulating this uniquely quantum phenomenon is what allows for quantum cryptography, communication, and computation. While parallels have been drawn between quantum entanglement and the classical physics of heat, new research demonstrates the limits of this comparison. Entanglement is even richer than we have given it credit for. T
The power of the second law
The second law of thermodynamics is often considered to be one of only a few physical laws that is absolutely and unquestionably true. The law states that the amount of ‘entropy’ — a physical property — of any closed system can never decrease. It adds an ‘arrow of time’ to everyday occurrences, determining which processes are reversible and which are not. It explains why an ice cube placed on a hot stove will always melt, and why compressed gas will always fly out of its container (and never back in) when a valve is opened to the atmosphere.
Only states of equal entropy and energy can be reversibly converted from one to the other. This reversibility condition led to the discovery of thermodynamic processes such as the (idealised) Carnot cycle, which poses an upper limit to how efficiently one can convert heat into work, or the other way around, by cycling a closed system through different temperatures and pressures. Our understanding of this process underpinned the rapid economic development during the Western Industrial Revolution.
Quantum entropy
The beauty of the second law of thermodynamics is its applicability to any macroscopic system, regardless of the microscopic details. In quantum systems, one of these details may be entanglement: a quantum connection that makes separated components of the system share properties. Intriguingly, quantum entanglement shares many profound similarities with thermodynamics, even though quantum systems are mostly studied in the microscopic regime. Scientists have uncovered a notion of ‘entanglement entropy’ that precisely mimics the role of the thermodynamical entropy, at least for idealised quantum systems that are perfectly isolated from their surroundings.

“Quantum entanglement is a key resource that underlies much of the power of future quantum computers. To make effective use of it, we need to learn how to manipulate it,” says quantum information researcher Ludovico Lami. A fundamental question became whether entanglement can always be reversibly manipulated, in direct analogy to the Carnot cycle. Crucially, this reversibility would need to hold, at least in theory, even for noisy (‘mixed’) quantum systems that have not been kept perfectly isolated from their environment.
It was conjectured that a ‘second law of entanglement’ could be established, embodied in a single function that would generalise the entanglement entropy and govern all entanglement manipulation protocols. This conjecture featured in a famous list of open problems in quantum information theory.
No second law of entanglement
Resolving this long-standing open question, research carried out by Lami (previously at University of Ulm and currently at QuSoft and the University of Amsterdam) and Bartosz Regula (University of Tokyo) demonstrates that manipulation of entanglement is fundamentally irreversible, putting to rest any hopes of establishing a second law of entanglement. This new result relies on the construction of a particular quantum state which is very ‘expensive’ to create using pure entanglement. Creating this state will always result in a loss of some of this entanglement, as the invested entanglement cannot be fully recovered. As a result, it is inherently impossible to transform this state into another and back again. The existence of such states was previously unknown.
Because the approach used here does not presuppose what exact transformation protocols are used, it rules out the reversibility of entanglement in all possible settings. It applies to all protocols, assuming they don’t generate new entanglement themselves. Lami explains: “Using entangling operations would be like running a distillery in which alcohol from elsewhere is secretly added to the beverage.”
Lami: “We can conclude that no single quantity, such as the entanglement entropy, can tell us everything there is to know about the allowed transformations of entangled physical systems. The theory of entanglement and thermodynamics are thus governed by fundamentally different and incompatible sets of laws.”
This may mean that describing quantum entanglement is not as simple as scientists had hoped. Rather than being a drawback, however, the vastly greater complexity of the theory of entanglement compared to the classical laws of thermodynamics may allow us to use entanglement to achieve feats that would otherwise be completely inconceivable. “For now, what we know for certain is that entanglement hides an even richer and more complicated structure that we had given it credit for,” concludes Lami. More