HKUST discovers novel elastic alloy achieving 20x temperature change and 90% carnot efficiency in solid-state heat pumping
2025-05-25
(Press-News.org)
Researchers at the School of Engineering of the Hong Kong University of Science and Technology (HKUST) have developed a novel elastic alloy called Ti₇₈Nb₂₂, which achieves remarkable efficiency for solid-state heat pumping and exhibits a reversible temperature change (ΔT) ability that is 20 times greater than that of conventional metals when stretched or compressed, offering a promising green alternative to traditional vapor-compression heating and cooling technologies.
Nearly half of the world’s energy is consumed for heating, including district heating in the building sector and process heating in various industrial sectors. Currently, global heat demand is primarily supplied by burning fossil fuels, which produce a large amount of greenhouse gases and consume significant energy. Using heat pumps based on solid-state phase transitions is a more eco-friendly approach, but their energy efficiency remains only 50–70% of the Carnot limit. Achieving more efficient and eco-friendly heat pumping remains a global challenge.
To address this challenge, Prof. SUN Qingping from the Department of Mechanical and Aerospace Engineering (MAE)’s research team has proposed a novel heat-pumping approach that utilizes heat generated by elastic deformation, known as the thermoelastic effect (TeE).
Although TeE was discovered by scientists Kelvin, Joule, and Duhamel in the 19th century, it was long considered too weak for practical applications. Prof. Sun’s team then fabricated a [100]-textured Ti₇₈Nb₂₂ martensitic polycrystal, which, when subjected to linear elastic deformation for heat pumping, exhibits a reversible temperature change (ΔT) of 4–5 K—20 times greater than conventional metals, which typically change only about 0.2 K. Remarkably, this alloy achieves approximately 90% of the Carnot efficiency limit in a heat-pumping cycle, making it highly competitive with refrigerants used in commercial vapor-compression heat pumps.
Furthermore, the team’s research indicates that certain ferroelastic alloys could be developed with even higher thermal expansion, achieving temperature changes of up to 22 K. This work provides a promising opportunity for the green heat pumping industry and presents the first non-phase-transition-based solution for eco-friendly, high-efficiency heat supply.
Prof. Sun said, “This discovery changes the long-standing and well-established perception that the thermoelastic effect is too weak to be useful. Our research demonstrates that linear elastic deformation alone can be used for highly energy-efficient heat pumping.”
Dr. LI Qiao, the first author of this study and Research Assistant Professor from the same department, added: “As global decarbonization efforts intensify, this technology provides a transformative solution for replacing fossil fuel-based heating. We are currently developing prototype heat pumps using the alloy for industrial applications.”
The study was recently published in Nature Communications, in a paper titled “Large Thermoelastic Effect in Martensitic Phase of Ferroelastic Alloys for High Efficiency Heat Pumping”. The research was supported by the Hong Kong Research Grants Council (RGC) through Strategic Topics Grant (STG) and General Research Fund (GRF). Related technologies have been filed for multiple international patents.
END
ELSE PRESS RELEASES FROM THIS DATE:
2025-05-24
Children born before 37 weeks of gestation have a considerably increased risk of dying before they reach the age of five. Predicting the risk of preterm birth (PTB) and hence implementing preventive strategies is complicated by the heterogeneity of the condition, the many unknown mechanisms involved, and the lack of reliable predictive tools. Now, however, researchers have been able to show that blood cell-free RNA (cfRNA) signatures can predict PTB over four months before delivery date, the annual conference of the European Society of Human Genetics will hear ...
2025-05-24
Lorundrostat, a novel therapy which blocks the production of aldosterone from the adrenal glands, demonstrated clinically meaningful and sustained reductions in blood pressure in 1,083 patients with uncontrolled or resistant hypertension, according to the results of a phase 3 trial announced today.
LONDON, UK – 24 May 2025 – The data from the Launch-HTN trial, announced at the 34th European Meeting on Hypertension and Cardiovascular Protection, show that lorundrostat, an aldosterone synthase inhibitor, is ...
2025-05-23
A case in which a sperm donor was later found to be carrying a cancer-causing pathogenic variant in his gametes has highlighted the problems of regulating gamete donation at European and international level, the annual conference of the European Society of Human Genetics will hear today (Saturday). Dr Edwige Kasper, a specialist in genetic predisposition to cancer at the Rouen University Hospital, Rouen, France, will say that the lack of cross-border regulation in Europe can result in the multiple use of gametes in families and risks inbreeding and the abnormal dissemination of inherited diseases.
Towards ...
2025-05-23
In biology, enzymes have evolved over millions of years to drive chemical reactions. Scientists from the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) now derived universal rules to enable the de novo design of optimal enzymes. As an example, they considered the enzymatic reaction of breaking a dimer into two monomer molecules. Considering the geometry of such an enzyme-substrate-complex, they identified three golden rules that should be considered to build a functional enzyme.
First, the interface of both enzyme and molecule should be located at their respective smaller end. This way, a strong coupling between both of them ...
2025-05-23
Jonathan Ajo-Franklin, a leading mind in applied geophysics and Trustee Professor of Earth, Environmental and Planetary Sciences at Rice University, has been awarded the 2025 Reginald Fessenden Award by the Society of Exploration Geophysicists. The honor recognizes a “specific technical contribution to exploration geophysics” that represents a major scientific or conceptual advancement — a distinction that places Ajo-Franklin among the most influential innovators in the field.
Ajo-Franklin is internationally recognized for ...
2025-05-23
Q: How would you summarize your study for a lay audience?
Our study investigated the role of astrocytes, an abundant cell type in the brain, in regulating an immune response against glioblastoma (GBM)—a highly aggressive brain cancer. We found a subset of astrocytes that limits the immune response and can be targeted with therapeutics.
Q: What question were you investigating?
GBM is a brain cancer that has remained untreatable for decades. Immunotherapies that have worked in other cancers are ineffective in GBM, potentially due to the local suppression of immune responses in the tumor microenvironment. Astrocytes are abundant ...
2025-05-23
HOUSTON – (May 23, 2025) – More than ten years ago, researchers at Rice University led by materials scientist Boris Yakobson predicted that boron atoms would cling too tightly to copper to form borophene, a flexible, metallic two-dimensional material with potential across electronics, energy and catalysis. Now, new research shows that prediction holds up, but not in the way anyone expected.
Unlike systems such as graphene on copper, where atoms may diffuse into the substrate without forming a distinct alloy, the ...
2025-05-23
Flowers grow stems, leaves and petals in a perfect pattern again and again. A new Cornell study shows that even in this precise, patterned formation in plants, gene activity inside individual cells is far more chaotic than it appears from the outside.
This finding has important implications for plant engineering, where scientists design artificial gene switches to control growth or behavior. Understanding how plants manage genetic “noise” could also inform research in other fields, from synthetic ...
2025-05-23
Q: How would you summarize your study for a lay audience?
Given the rise in brain-based conditions and the growing development and investment in neurotechnologies to target them, it is important to understand how the public views these interventions and whether they would be willing to use them. To explore this, we conducted a survey of over 1,000 U.S. adults to examine perceptions of four neurotechnologies designed to treat severe mood, memory, or motor symptoms.
Q: What question were you investigating?
One of the goals of the recently created Neurotech Justice Accelerator at Mass General Brigham (NJAM), a Dana Center for Neuroscience & Society, is to better ...
2025-05-23
NEW ORLEANS, May 23, 2025 – When children are dropped off at a school or day care for the first time, there can be a lot of feelings and sometimes meltdowns caused by being separated from parents, meeting new people, and hearing new noises. Could the architecture of the room help to soothe at least some of the children’s concerns?
“Classrooms without any sound absorption are the majority in Japan,” said Ikuri Matsuoka, a master’s student at Kumamoto University in Japan. “My motivation was to make people aware of the importance of acoustics in classrooms because in Japan, there are no standards ...
LAST 30 PRESS RELEASES:
[Press-News.org] HKUST discovers novel elastic alloy achieving 20x temperature change and 90% carnot efficiency in solid-state heat pumping
