A thermal memory device designed to enable intelligent heat management

A study led by the University of Barcelona addresses one of the major challenges of modern electronics: controlling heat in electronic devices.

University of Barcelona

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Professor Eric Langenberg, from the Department of Condensed Matter Physics at the Faculty of Physics and the Institute of Nanoscience and Nanotechnology (IN2UB) at the University of Barcelona. 

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Credit: UNIVERSITY OF BARCELONA

Heat is the main source of energy loss in most industrial processes and in electronic devices. To manage and reuse heat more efficiently, a study led by the University of Barcelona has developed a thermal memory prototype capable of controlling heat flow with small electrical voltages. This innovation, published in the journal Advanced Materials, has potential implications for intelligent heat management, energy conversion and thermal energy harvesting.

The study is led by Professor Eric Langenberg, from the Department of Condensed Matter Physics at the Faculty of Physics and the Institute of Nanoscience and Nanotechnology (IN2UB) at the UB, and the first author is expert Dídac Barneo (UB-IN2UB).

Also taking part are experts from the Center for Research in Biological Chemistry and Molecular Materials  (CiQUS), based at the University of Santiago de Compostela; the Materials Science Institute of Madrid (ICMM-CSIC); the Institute of Materials Science of Barcelona (ICMAB-CSIC); and the University of Zaragoza (UNIZAR).

Controlling heat in electronic devices

The study addresses one of the major challenges of modern electronics: controlling heat in electronic devices. “This research could pave the way for the development of a new information storage technology based on heat rather than electricity,” says Professor Langenberg.

The prototype consists of a solid structure formed by a gold layer on top of an ultra-thin layer (seven nanometres thick) of a ferroelectric hafnium-zirconium oxide (Hf0.5Zr0.5O2), which is deposited on an oxygen-ion conductive substrate. (yttria-stabilised zirconia, YSZ).

When small voltages are applied between the gold and the substrate, the thermal conductivity of the ferroelectric oxide reversibly switches between two states: high thermal conductivity (with positive voltages) or low thermal conductivity (with negative voltages).

“The applied voltage makes it possible to define two different thermal states and to modulate at will the ease with which heat passes through the material. Since these two thermal-conductivity states remain stable even when the voltage is removed, the device becomes a non-volatile thermal memory," explains Langenberg.

This behaviour is based on a physical mechanism never before employed to control heat transport with an electric field: the coupling of ferroelectric polarization with the migration of oxygen vacancies. These vacancies are small defects that scatter photons and hinder their passage. Photons are the basic unit of vibration in solid structures, much as electrons do in the case of electricity. “Thus, a high concentration of oxygen vacancies in the ferroelectric oxide hafnium zirconium oxide will impede the passage of phonons (low thermal conductivity), in contrast to a low concentration of vacancies (high thermal conductivity),” explains Dídac Barneo, also a member of the Department of Condensed Matter Physics.

These oxygen vacancies can move through the solid structure under an electric field. Negative voltages attract these vacancies, whereas positive voltages repel them. “If a negative voltage is applied though the gold layer, the ferroelectric oxide exhibits low thermal conductivity. Conversely, when positive voltages are applied, the result is high thermal conductivity,” notes Barneo.

But the applied voltage alone cannot explain the memory phenomenon. “There is a crucial component for memory functionality and the stability of thermal states: the polarization of the ferroelectric oxide, which acts as a valve that prevents the oxygen vacancies from redistributing themselves when the voltage is removed. This effect allows the two thermal states to be preserved and turns the device into a thermal memory,” the experts say.

From electrons to phonons: challenges in solid-state physics

This device is the first functional prototype developed within the e-PHONONBIT project (Design of phononic bits with electrical control in films and epitaxial superstructures based on ferroelectric oxides), which is led by Professor Langenberg. As part of the study, the UB team devised the physical mechanism that explains the operation of thermal memory, coordinated the various experimental and theoretical collaborations and integrated all the data into the study’s overall interpretation.

In the future, the performance of the new device will need to be improved in order to increase the difference in thermal conductivity between the two states, enable it to operate at room temperature (it currently operates at 200°C) and to reduce the switching time between the two thermal states (from minutes to milliseconds).

“The idea is to explore different combinations of ferroelectric materials, ionic conductors (in particular, oxygen vacancies) and substrates to address these three challenges,” explains Eric Langenberg.

“In the longer term, we aim to develop new computing architectures based on phonons. Controlling phonon transport with an electric field is quite a challenge in solid-state physics. We are at the dawn of phononics; only time will tell how far this new discipline will take us,” the researcher concludes.

This research could pave the way for the development of a new information storage technology based on heat rather than electricity.

  

This device is the first functional prototype developed within the e-PHONONBIT project (Design of phononic bits with electrical control in films and epitaxial superstructures based on ferroelectric oxides), which is led by Professor Eric Langenberg. 

A thermal memory device designed to enable intelligent heat management [AUDIO] 

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Journal

Advanced Materials

DOI

10.1002/adma.202519670. 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

The Coupling of Ferroelectric Polarization and Oxygen Vacancy Migration Enables Electrically Controlled Thermal Memories

 

Improving spikelet production efficiency crucial for unleashing yield potential in rice

KeAi Communications Co., Ltd.

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Fig. 1. Correlation of spikelet production efficiency (SPE) with grain yield, harvest index, post-anthesis leaf photosynthetic rate, shoot dry matter accumulation, and NSC remobilization rate in rice.

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Credit: Zhang W Y et al.

Rice grain yield hinges on four components: panicle number, spikelets per panicle, filled-grain rate, and grain weight. Among these, spikelets per panicle offers the greatest untapped potential. However, simply increasing spikelet number requires a proportional increase in vegetative biomass, which limits yield gains. A more efficient route, therefore, is to produce more spikelets per unit of biomass–a concept the researchers term spikelet production efficiency (SPE).

“SPE is defined as the number of differentiated spikelets per panicle divided by the dry weight of vegetative organs (culm, leaves, and sheaths) per shoot at the spikelet differentiation stage,” explains Prof. Jianchang Yang, corresponding author of a new study in the field. “It measures how efficiently a rice plant converts vegetative growth into reproductive sink capacity.”

SPE provides a physiological criterion to evaluate how efficiently a rice plant converts vegetative biomass into reproductive sink capacity. “Our analyses show that SPE is linearly and positively correlated with grain yield and harvest index, with correlation coefficients even higher than those for vegetative organ dry weight alone,” adds Yang.

By comparing multiple rice varieties grown under high-yielding populations, the team found that higher SPE varieties produced more spikelets per panicle and achieved greater grain yield and harvest index. “Higher SPE did not reduce filled-grain rate or 1,000-grain weight,” says Dr. Weiyang Zhang, first author and co‑corresponding author of the study. “Moreover, it was associated with improved post-anthesis leaf photosynthesis, shoot dry matter accumulation, and non-structural carbohydrate (NSC) remobilization from stems.”

These findings suggest that a larger sink capacity actively “pulls” photoassimilates from source organs, enhancing the rice plant’s overall carbon economy.

“Improving SPE could serve as a new key criterion for breeding super-high-yield rice varieties and developing cultivation strategies,” adds Zhang. “We are now investigating the genetic and molecular mechanisms underlying SPE to provide novel insights for rice improvement.”

The team published their findings in the Journal of Integrative Agriculture.

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Contact Authors:

Weiyang Zhang, E-mail: wyz@yzu.edu.cn;

Jianchang Yang, E-mail: jcyang@yzu.edu.cn

The publisher KeAi was established by Elsevier and China Science Publishing & Media Ltd to unfold quality research globally. In 2013, our focus shifted to open access publishing. We now proudly publish more than 200 world-class, open access, English language journals, spanning all scientific disciplines. Many of these are titles we publish in partnership with prestigious societies and academic institutions, such as the National Natural Science Foundation of China (NSFC).

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Journal

Journal of Integrative Agriculture

DOI

10.1016/j.jia.2026.03.041 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Improving spikelet production efficiency is crucial for further unleashing yield potential in rice

 

Why moths have a preferred side: Smart solutions for small brains

Just as humans exhibit right- or left-handedness, moths also have a preferred side on which they place their proboscis when inspecting a flower for nectar.

University of Konstanz

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Most people have a preferred hand for tasks such as writing or grabbing a cup of coffee. The same applies to the feet – for example, when playing soccer. Similar preferences are also found across many other animals: birds, octopuses, and insects, among others, often favor either their left or right leg, arm, or antenna when performing specific actions. This so-called lateralization is widespread throughout the animal kingdom and occurs in organisms with a wide variety of nervous systems.

But what about appendages that an animal has only one of – such as our tongue or an elephant’s trunk? Even in these cases, lateralization can occur. In their latest study published in PNAS, research led by Lochlan Walsh and Anna Stöckl from the University of Konstanz demonstrated one such example: Their findings reveal that hummingbird hawkmoths – a day-active moth species that suckle nectar from flowers like their namesakes – have a preferred side to which they extend their tongue-like proboscis while inspecting flowers for nectar. This may be a solution that nature has developed to enable precise control of actions even in organisms with comparatively simple nervous systems.

A moth’s version of handedness
To determine the side to which hummingbird hawkmoths extend their long proboscis, the researchers presented the insects with artificial flower surfaces that the animals approached and inspected. Using high-speed cameras and computer-vision tools, they were then able to reconstruct the proboscis movements in detail and track them relative to the rest of the body.

The researchers found that some individuals tended to place the tip of their proboscis predominantly to the left of their body’s midline while inspecting a flower, whereas others showed a preference for the right side. The strength of this side preference varied between individuals, much as the strength of handedness does in humans. What is more, the individual side preference was already evident from the beginning of the experiment rather than emerging with increasing experience. “This suggests that proboscis lateralization is an innate trait and that it plays an important role in guiding the moths’ flower-inspection behaviour,” says Stöckl.

Touch where you look
In a further step, the researchers simulated the animals’ visual field during flower exploration. They found that hummingbird hawkmoths not only had a preferred side for placing their proboscis, but also a dominant eye for viewing the part of the flower they were touching. The side of this dominant eye consistently matched the side on which the proboscis was preferentially positioned. “Insects have quite small brains. Aligning the proboscis with the visual field of the dominant eye can save valuable processing capacity when controlling behavior. Rather than constantly recalculating a movement from every possible angle, the animal can rely on a familiar side of its body to guide its actions”, Walsh explains.

What came as a surprise was that the alignment of the proboscis with the visual field of the dominant eye was maintained even when part of that eye was experimentally occluded. “Humans or birds would adapt in such a situation by moving their limb into the visual field of the unobstructed eye. Hummingbird hawkmoths, by contrast, adjust their body position on the flower so that they can view it with the uncovered portion of the dominant eye and preserve their original eye-proboscis strategy,” Walsh says. As a result of the limited computational capacity of their brains, the moths seem to depend on this efficient coordination of the dominant eye and the proboscis.

Taken together, the findings show that precise, flexible behavior does not require a large brain. “Instead, animals can rely on efficient shortcuts built into the relationship between the body, the senses, and movement,” Stöckl explains. In hummingbird hawkmoths, one such shortcut is the eye and proboscis working as a coordinated unit. “Each moth solves the challenge of flower inspection through the side preferences of its own body. Our study therefore suggests that lateralization may be one of nature's ways of simplifying difficult tasks – whether that task is reaching for a coffee cup or using the proboscis to search for nectar while hovering in front of a flower.”

 

Key facts:

• Original publication: L. Walsh, S.M. Kannegieser, A.L. Stöckl (2026). Conservation of a lateralized visuomotor axis in hawkmoth proboscis probing. PNAS; DOI: 10.1073/pnas.2609365123
• Anna Stöckl is a junior professor of neurobiology and behavior and an Emmy Noether research group leader at the University of Konstanz. She is also a member of the Centre for the Advanced Study of Collective Behaviour (CASCB) and a Fellow at the Zukunftskolleg of the University of Konstanz. Research group website: https://www.insect-vision.com/
• Lochlan Walsh is a doctoral researcher in the department of Biology at the University of Konstanz. He is also affiliated with the International Max Planck Research School for Quantitative Behaviour, Ecology & Evolution and supported by the Hector Fellow Academy.
• The Centre for the Advanced Study of Collective Behaviour at the University of Konstanz is an interdisciplinary research centre that studies the principles behind the collective behaviour of animals and other systems.
• Funding: Bavarian Academy of Sciences, Hector Fellow Academy, German Research Foundation (DFG; Emmy Noether Programme) and the Zukunftskolleg of the University of Konstanz.

 

Note to editors:

A selection of images and video material is available for download at:

 

Image 1: https://www.uni-konstanz.de/fileadmin/pi/fileserver/2026_extra/why_moths_have_a_preferred_side1.jpg 
Caption: A hummingbird hawkmoth hovers in front of a flower while using its proboscis to feed from flower nectar.
Credit: Anna Lisa Stöckl

Image 2: https://www.uni-konstanz.de/fileadmin/pi/fileserver/2026_extra/why_moths_have_a_preferred_side2.jpg  
Caption: A hummingbird hawkmoth hovers in front of a flower while using its proboscis to feed from flower nectar.
Credit: Anna Lisa Stöckl

Video 1: https://www.youtube.com/watch?v=8LeCyMbiB7U
Caption: Example snippet of visual field simulation to show how behavioural videos were transformed into an estimation of where the hawkmoths were looking.
Credit: Lochlan Walsh

Video 2: https://www.youtube.com/shorts/KCudJxmMgJw
Caption: Example snippet of a hawkmoth inspecting the flower surface with the proboscis, overlaid with tracked body parts.
Credit: Lochlan Walsh

 

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DOI

10.1073/pnas.2609365123 

 

Transcending natural evolution: How humanity can shape its own future

Science China Press

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Diagram showing human brain size stabilising over 300,000 years while technological capability accelerates from stone tools toward AGI.

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Credit: ©Science China Press

Evolutionary Tempo Mismatch: Biological Evolution Unfolds over Millennia, Technological Iteration within a Decade

Human biological evolution and advances in artificial intelligence unfold on markedly different timescales.

From the perspective of natural evolution, the human body and brain were shaped over immense spans of time. Archaeological and anthropological research indicates that modern human brain volume had already approached its present level around 300,000 years ago, while the brain’s basic structure and modes of information transmission have changed very little. The human brain operates on roughly 20 watts of metabolic power; neural signals propagate at about 1 to 100 metres per second; and individual neurons typically fire no faster than 100 to 200 hertz. Cranial volume, heat dissipation, and metabolic homeostasis together constrain cognitive bandwidth, working memory, and parallel processing speed. Neuroplasticity enables people to learn and adapt, but it relies mainly on slow, localised synaptic updates and cannot compensate for the pace of biological evolution over millennia.

By contrast, AI systems are now updated on timescales of years, months, or even weeks. Current training frameworks can coordinate tens of thousands of specialised processors and perform synchronised computation at gigahertz clock speeds. Frontier-model architectures and safety mitigations can be reconfigured within weeks or months and redeployed across global infrastructure. On the hardware side, memristive in-memory computing systems, two-dimensional materials, and advanced thermal-management technologies are being developed to overcome bottlenecks in conventional computing architectures. This speed and scale far exceed biological evolution, but they do not make AI inherently more energy-efficient: training and operating large models still require vast amounts of electricity, cooling, data-centre capacity, and complex global supply chains.

The paper describes the disparity between millennial-scale biological evolution and sub-decadal algorithmic iteration as an “evolutionary tempo mismatch”. This is not simply a comparison of human and machine speed. It points to a structural tension: technological capabilities are expanding rapidly, while human biology and social institutions cannot change at the same pace.

In response to this mismatch, the paper proposes “transcending natural evolution”: using technology to advance and augment human perceptual, cognitive, and motor capabilities at a pace beyond natural evolution.

Crossing the Embodiment Threshold: AI Moves from the Digital Realm to Embodied Interaction

The embodiment threshold describes the transition from largely digital inference to continuous participation in physical, bodily, or neural activity.

AI has long operated mainly in the digital realm, processing symbolic information such as text, images, and code. Its outputs can shape human judgement and decision-making, but the systems themselves have generally lacked a closed loop through which they continuously sense the environment, act, and receive feedback. In this sense, they remain forms of disembodied intelligence.

Recent advances in multimodal models, robotics, and bioelectronics are beginning to blur this boundary. An AI system crosses the embodiment threshold when it forms a task-relevant closed loop with a physical environment, the human body, or neural tissue, supported by persistent or continuously available integration and sensory-motor coupling. This is not a binary boundary but a graded continuum. Robots that navigate and manipulate objects, wearable devices that continuously monitor physiological signals, and brain-computer interfaces that directly read or modulate neural activity represent different degrees of embodiment.

Flexible bioelectronics provide a critical material interface for sustained interaction between AI systems and the human body. Rigid silicon devices and soft biological tissues differ by several orders of magnitude in mechanical stiffness, so long-term wear or implantation may cause microtrauma, localised inflammation, and signal degradation. Surface-wrinkling techniques, nanoscale-ribbon buckling, self-healing structures, and textile electronics are improving device conformability, stretchability, and stability. Examples reviewed in the paper include smart textiles that monitor glucose and cortisol, artificial throats that capture laryngeal myoelectric signals and mechanical vibrations, and endovascular stent-electrode arrays delivered through the jugular vein to vessels adjacent to the motor cortex. These technologies show different routes from body-surface sensing to neural interfaces, but challenges remain in scalable manufacturing, biocompatibility, long-term signal stability, and power delivery.

This trajectory spans three continuous operational domains: disembodied intelligence in the digital domain, embodied intelligence in the physical domain, and human-machine integration in the neural domain. As interaction bandwidth increases, connections become more persistent, and information flows become bidirectional, AI may increasingly serve as an extension of human perception, communication, and movement. Whether this progression leads to deeper human-machine symbiosis will still depend on safety, ethical boundaries, and social governance.

Biological-Technological Stratification: Human-Machine Integration and Governance under Resource Constraints

Human-machine integration does not automatically guarantee a better future. The expansion of computing capacity and the wider adoption of bioelectronic interfaces are constrained by energy, materials, supply chains, and institutional conditions. These constraints directly shape who controls the technology and who can use it.

The paper calls the durable divide that could emerge “biological-technological stratification”. If high-bandwidth cognitive assistance, restoration of neural function, and predictive health monitoring remain available mainly to the few who can afford them, social inequality could extend beyond income and resources into cognitive bandwidth, physical capability, and health security. At the same time, large models trained on existing corpora and optimised for majority preferences may intensify cognitive convergence. If neural signals are collected and traded as ordinary consumer data, the protections surrounding neural privacy and biological intent will also be put at risk.

To address these risks, the paper proposes an adaptive governance roadmap. Rather than a three-phase plan tied to fixed calendar dates, it calls for different levels of oversight to be triggered by measurable technological indicators and the depth of human-machine integration.

Phase I focuses on infrastructural legibility. At the point of frontier-model release, it calls for standardised disclosure of compute allocation, energy use, and training-data provenance, together with immutable incident logs, rigorous red-teaming, and independent evaluation. As wearable and non-invasive interfaces develop, raw neural signals should also be placed under stringent protections for medical or sensitive data.

Once AI crosses the embodiment threshold, Phase II shifts the focus to embodied safety and user autonomy. Priorities include harmonised engineering and clinical standards, continuous assessment of algorithmic drift, robust software and physical fail-safes, and a functional right to disconnect. Legal frameworks will also need to distinguish among biological intent, algorithmic recommendation, and device-level execution when assigning responsibility.

Phase III addresses transnational equity. Drawing organisational lessons from the European Organization for Nuclear Research (CERN) and the International Atomic Energy Agency (IAEA), the paper recommends exploring cross-border oversight and public-interest review mechanisms, broadening access to baseline computational infrastructure and predictive health monitoring, and reducing dependence on a small number of large cloud platforms and actors that control critical supply chains.

Conclusion and Outlook

As humanity moves from natural evolution to what the paper calls transcending natural evolution, it faces a choice about how its future will be shaped. The value of this Position Paper lies not in forecasting specific technological milestones, but in placing people back at the centre of the debate: How should technology expand human capabilities, and what structural changes might follow for society? The paper argues that the goal should not be the unconstrained expansion of machine capability. It should be to keep the enhancement of human perception, cognition, and action at the centre of technological development, and to guide intelligent technologies and their governance so that humanity retains the agency to shape its future.

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Journal

Science China Information Sciences

DOI

10.1007/s11432-026-5041-7 

 

Crowd reactions influence whether people receive controversial political messages positively or negatively

Aston University

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• Psychologist Dr Carl Senior at Aston University carried out research to look at people’s responses to an anti-immigration message from Nigel Farage
• The message was accompanied by either no reaction, applause, laughter, booing, or mixed laughter and booing
• Applause and laughter led to a more positive response from viewers, while mixed laughter and booing was especially damaging.

Positive crowd reactions like applause and laughter can make controversial political messages more acceptable to viewers, according to new research by psychologist Dr Carl Senior at Aston University.

The research suggests that how broadcasters and content creators use applause, laughter, and booing can subtly shape public perceptions of populist figures and divisive issues like immigration.

In carrying out the study, Dr Senior collaborated with Professor Patrick Stewart at the University of Arkansas, US, and Professor Erik Bucy at Texas Tech University, US. They played a 1m 19s clip of populist UK politician Nigel Farage attacking UK immigration policy. Immigration is a divisive topic in both the UK and the US.

The clip was shown to study participants with one of five soundtracks – no reaction, audience applause, laughter, booing, or mixed laughter and booing. They were then asked to rate the pleasantness of the clip and their perceptions of whether Farage ‘met expectations’ and ‘met his goals’.

When the message was shown with positive crowd responses, such as laughter and applause, participants rated the message as more successful and acceptable. A crowd response of mixed laughter and booing was particularly damaging, reducing pleasantness ratings compared with applause, laughter, and even the control condition.

Their findings show that studio audiences, crowd shots, and reaction tracks do more than provide ‘colour’. They can nudge how at home viewers judge a controversial leader without changing a single word of the speech, or the images shown. People do not just react to what a politician says, but also to contextual cues.

A viewer’s political ideology, as well as their country of origin, had an important effect on their perception of Farage and his message. More conservative participants and those in the US generally rated Farage as more pleasant, more successful, and more supportive of group values than participants in the UK.

The researchers say that future work could use other assessment methods such facial coding and facial electromyography (methods to track the movements of facial muscles) or vocal acoustics to more precisely track people’s emotional responses in the moment. They also call for studies to directly measure viewers’ familiarity with a politician, and for work that explicitly tests how audience response interacts with country and ideology to shape evaluations of leaders and their messages.

Dr Senior said:

“We wanted to test a more nuanced model of emotion in a real political case, moving beyond simple ‘like/dislike’ or basic emotion labels to examine how people appraise relevance, implications, coping, and norms when they watch a political message. We chose Farage because he is a controversial and high profile populist whose rhetoric on immigration is both consequential and polarising, making him an ideal case for studying how nonverbal cues and audience reactions influence evaluations across different national and ideological contexts.” 

Visit www.frontiersin.org/journals/political-science/articles/10.3389/fpos.2026.1721738/full to read the full paper, ‘Facing Farage: Using the Componential Processing Model of emotion to understand cross-national response to manipulated video of Nigel Farage’ in Frontiers in Political Science.

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Journal

Frontiers in Political Science

DOI

10.3389/fpos.2026.1721738 

Method of Research

Observational study

Subject of Research

People

Article Title

Facing Farage: using the componential processing model of emotion to understand cross-national response to manipulated video of Nigel Farage

Article Publication Date

22-Jul-2026