MICROFLUIDICS - Laboratory for refrigeration and district energy

Thermag XI 2026: A successful gathering of the solid-state thermal community

admin — Tue, 16 Jun 2026 06:01:05 +0000

The 11th IIR Conference on Solid-State Cooling, Heating and Energy Harvesting – Thermag XI, held from 7-11 June in Ljubljana, Slovenia, has concluded successfully.

This milestone event brought together researchers, engineers, and industry experts from around the world to exchange the latest advances in solid-state cooling, heating, and energy harvesting. Thermag XI provided a unique forum for sharing cutting-edge research on functional materials, emerging concepts, and their integration into next-generation energy systems.

The presentations reflected a wide range of research activities, from fundamental studies and materials development to device prototyping, modelling, and practical applications that contribute to more sustainable energy technologies. The conference proceedings will be published soon on the IIR website: https://iifiir.org/en/conference-proceedings.

We sincerely thank all authors for their submissions and the reviewers for their valuable contributions. Special appreciation goes to the keynote speakers, session chairs, scientific committee, and organizing team whose efforts made the event possible. We also gratefully acknowledge the support of the International Institute of Refrigeration (IIR), the Slovenian Energy Association (SZE), the Chinese Association of Refrigeration (CAR), the Faculty of Mechanical Engineering at the University of Ljubljana, and all sponsors and partners.

The following topics were presented:

THE CONVENTIONAL AND ROTATING MAGNETOCALORIC EFFECT OF A GADOLINIUM PARALLEL PLATE MAGNETIC REGENERATOR – INFLUENCE OF GEOMETRY (Rafael Almeida, Rodrigo Kiefe, Darja Gačnik, Ricardo M. C. Pinto, João O. Silva, Katja Klinar, Henrique Souza, Gonçalo Oliveira, João S. Amaral, Andrej Kitanovski, João H. Belo)

IMPLEMENTATION AND VALIDATION OF AN ACTIVE ELECTROCALORIC REGENERATOR COMPONENT IN TCC BUILDER (Grega Belšak, Izak Oberčkal Pluško, Katja Vozel, Andrej Kitanovski, Markys Cain, Katja Klinar)

NUMERICAL STUDY ON THE FREQUENCY DEPENDENCE OF THE DIRECT MAGNETOCALORIC EFFECT OF GADOLINIUM FILM (Zhonghao Chang, Jorge Revuelta-Losada, Erika Fontana, Nora Dempsey, Katja Klinar, Andrej Kitanovski, Jia Yan Law, Victorino Franco)

VALIDATION OF THE NUMERICAL SIMULATION OF A HIGH-FREQUENCY REGENERATIVE THERMOMAGNETIC GENERATOR HYPEREG (Kamyar Dobakhti, Katja Klinar, Urban Tomc, Jure Javornik, Andrej Kitanovski)

FINITE ELEMENT MODELING AND OPTIMIZATION OF A MAGNETIC FIELD SOURCE FOR THERMOMAGNETIC GENERATION (Radel Gimaev, Katja Klinar, Andrej Kitanovski)

NUMERICAL MODELING OF AN ACTIVE MAGNETIC REGENERATOR BASED ON THE ROTATIONAL MAGNETOCALORIC EFFECT (Radel Gimaev, Darja Gačnika, Urban Tomc, Rafael Almeida, Rodrigo Kiefe, João H. Belo, João S. Amaral, Katja Klinar, Andrej Kitanovski)

PHASE-CHANGE MATERIAL THERMAL DIODES FOR CALORIC REFRIGERATOR (Karl Joulain, Katja Klinar, Katja Vozel, Andrej Kitanovski, Younès Ezzahri)

A GENERALIZED MODELLING APPROACH FOR ACTIVE ELECTROCALORIC REGENERATORS (Matija Kalin, Darja Gačnik, Katja Klinar, Andrej Kitanovski)

HYPEREG: HIGH-FREQUENCY MAGNETOCALORIC REGENERATOR (Andrej Kitanovski, Katja Klinar, Jure Javornik, Simon Nosan, Jakob Perne, Simon Bogić, Blaž Jagodic, Urban Tomc)

THE PERSPECTIVES OF ULTRA-HIGH-TEMPERATURE SOLID-STATE HEAT PUMPS (Katja Klinar, Darja Gačnik, Radel Gimaev, Andrej Kitanovski)

BRIDGING THE THERMAL GAP: THE ROLE OF FLUIDIC AND MECHANICAL THERMAL CONTROL DEVICES IN ADVANCING CALORIC TECHNOLOGIES (Katja Klinar, Urban Tomc, Katja Vozel, Andrej Kitanovski)

THERMAL CONDUCTIVITY OF CELLULOSE-BASED COMPOSITE FILMS (Vanja Kokol, Vera Vivod, Katja Klinar)

MODELING OF THERMOACOUSTIC GENERATOR IN TCCBUILDER (Izak Oberčkal Pluško, Harini Nivetha Raja, Grega Belšak, Jingyuan Xu, Katja Vozel, Andrej Kitanovski, Katja Klinar)

EVALUATION OF CURIE TEMPERATURE EFFECTS IN THE PERFORMANCE OF ACTIVE MAGNETIC REGENERATORS – PART I: SECOND ORDER PHASE TRANSITION (Urban Tomc, Guilherme F. Peixer, Chistian R. H. Bahl, Kaspar K. Nielsen, Jaime A. Lozano, Jader R. Barbosa Jr., Andrej Kitanovski)

DIGITAL MICROFLUIDIC THERMAL SWITCH CAPACITORS FOR MAGNETOCALORIC COOLING (Blaž Velkavrh, Hana Uršič, Urška Erjavec Nagode, Andrej Kitanovski, Lukas Beyer, Jens Freudenberger, Klara Lünser, Enric Stern-Taulats, Lluis Mañosa, Urban Tomc)

ENHANCING SOLID-STATE THERMAL RECTIFICATION VIA TEMPERATURE-DEPENDENT THERMAL CONTACT RESISTANCE (Katja Vozel, Andrej Kitanovski)

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Cool BatMan featured as M-ERA.NET Success Story

admin — Tue, 10 Feb 2026 13:40:49 +0000

The Cool BatMan project has been recognized as a Success Story by M-ERA.NET.

The project aimed to build a fundamental understanding of the dynamic thermal behavior of a compact cooling concept. It combines magnetocaloric materials, exploiting the magnetocaloric effect, with electrowetting-on-dielectric (EWOD) digital microfluidics. The work included advanced microfabrication and new characterization approaches.

A key outcome is the demonstration that digital microfluidics, widely used in bioanalytical lab-on-a-chip systems, also has strong potential for thermal management at the mini- and microscale.

We thank our consortium partners: Jožef Stefan Institute, Leibniz Institute for Solid State and Materials Research Dresden, and the University of Barcelona. We also thank M-ERA.NET for the recognition.

Read the full success story here:
https://www.m-era.net/news/successtory_coolbatman

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Airbrushing: A Novel Method for Preparation of High‐Emissivity Black Coating for Infrared Measurements

admin — Fri, 05 Sep 2025 17:52:59 +0000

The article “Airbrushing: A Novel Method for Preparation of High‐Emissivity Black Coating for Infrared Measurements“, published in the journal Advanced Materials Interfaces (IF = 4.4), presents a new method for applying high-emissivity black coatings intended for infrared (IR) temperature measurements.

Researchers from the Laboratory for Refrigeration and District Energy (Process Engineering) collaborated on the study with colleagues from the Jožef Stefan Institute, the National Institute of Chemistry, the Colorado School of Mines, and the University of Barcelona.

Using a simple and cost-effective airbrush system, we developed a procedure for applying a homogeneous and thin black coating layer (minimum thickness of 3 µm), which can be deposited on various shapes and materials—including curved surfaces. The average emissivity of the coating is approximately 0.95 in the 0.5–2.5 µm spectral range, enabling high-precision IR temperature measurements even on surfaces with naturally low emissivity (e.g., metals).

The effectiveness of the method was demonstrated by direct IR temperature measurements of the magnetocaloric effect on a LaFeCoSi magnetocaloric material sample, where the results showed excellent agreement with the manufacturer’s technical data. The coating is fully removable with standard laboratory solvents, allowing temporary application without affecting the sample properties.

This new method combines the advantages of conventional painting and printing techniques and opens up possibilities for more precise thermal characterization of caloric materials and other samples where high emissivity is essential for IR measurements.

Figure: a) Photograph of the airbrush used in this work; b) Schematic representation of coating procedure; c) Average total coating thickness as a function of number of layers; d) Temperature profile of a coated magnetocaloric plate under a cycling applied magnetic field 0 – 1.1 T.

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FisMat 2025, Venice

admin — Thu, 10 Jul 2025 12:24:59 +0000

At this year’s FisMat conference, held in Venice, Italy, a special workshop on cooling of electronics and sensors took place. As part of the workshop, Katja Klinar gave an invited talk titled “Active and Passive Cooling Methods for Electronics and Sensors.”

The workshop provided an excellent opportunity for an in-depth look at the latest research and innovative solutions in one of the key areas of modern electronics. The high quality of the presentations, the diversity of approaches, and the engaging discussions clearly demonstrated how important and timely this field is.

Sincere thanks to the organizers for a carefully planned and content-rich workshop. It’s always encouraging to see a community so committed to progress—both in scientific understanding and practical application.

More info: https://eventi.cnism.it/fismat2025

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TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits

admin — Mon, 11 Nov 2024 07:21:40 +0000

Researchers of the LAHDE laboratory of the Faculty of Mechanical Engineering, University of Ljubljana, have developed an open-source tool for 1D modeling of thermal control circuits, TCCbuilder. It is the first tool of its kind that enables quick and easy modeling of thermal control circuits thanks to its graphical user interface and thr associated library of materials used to create thermal control elements.

In addition to the library of materials, there is also a library of already designed thermal control elements from the literature. Researchers from various fields are invited to complement both libraries as well as to add functionality to the tool. Thus, TCCbuilder is not only an indispensable tool for simulations, but also a platform for the exchange of information and networking of researchers in the field of heat transfer and materials.

The tool is presented in the article TCCbuilder: an open-source tool for the analysis of thermal switches, thermal diodes, thermal regulators, and thermal control circuits, which describes the validation and examples of the use of the tool. The article is published in the journal iScience (IF = 4.6), Special Issue: Advanced thermal control: fundamentals and applications.

The article is freely accessible under the following link: https://doi.org/10.1016/j.isci.2024.111263

Summary:

In the area of thermal management, thermal control elements (TCEs) and thermal control circuits (TCCs) are proving to be innovative solutions to the challenges of temperature control and heat dissipation in various applications, ranging from electronic cooling to energy conversion and temperature control in buildings. Their integration promises to improve power density, energy efficiency, system reliability and system life expectancy. With the aim of connecting researchers in the field of thermal management and accelerating the development of TCEs and TCCs, we have developed an open-source TCC simulation tool called TCCbuilder that enables a quick and easy time-dependent 1D numerical analysis of the behavior of TCEs and TCCs. It uses the heat conduction equation to solve temperature profiles in different devices. The TCCbuilder application offers features not previously available with any other TCC modelling tool: a large adjacent library of materials and TCEs as well as a user-friendly graphical user interface (GUI).

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SDEWES 2024

admin — Mon, 16 Sep 2024 05:20:19 +0000

The SDEWES 2024 conference in Rome was a truly remarkable event, bringing together leaders, researchers, and professionals dedicated to advancing sustainable development and energy systems. As one of the premier conferences in this field, SDEWES provided a unique platform for exchanging cutting-edge ideas and fostering collaborations that can drive global change.

Throughout the conference, a wide range of topics were covered, from renewable energy integration and smart grids to circular economy principles and sustainable urban planning. The diversity of perspectives and the depth of the discussions were nothing short of inspiring. It was clear that the collective expertise and passion of the attendees are key to addressing the complex challenges we face in creating a more sustainable future.

The LAHDE’s contribution to the conference was a presentation by Katja Klinar, who shared insights on “Heat Pump Modelling in District Heating and Cooling Grid.” This work is a crucial part of the SenergyNets project, which is paving the way for more efficient and sustainable energy systems.

Attending SDEWES 2024 was a powerful reminder of the importance of collaboration across disciplines and borders. The ideas and connections forged here will undoubtedly have a lasting impact on the future of sustainable energy and development.

Looking forward to continuing the journey with this incredible community and applying the insights gained from this experience.

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LAHDE Team Attends Thermag 2024 and Visits the World’s Largest Rare Earth Manufacturing Hub

admin — Tue, 27 Aug 2024 09:42:30 +0000

The LAHDE team recently had the privilege of attending the 10th IIR Conference on Caloric Cooling and Applications of Caloric Materials (THERMAG 2024) in Baotou, China. This event was particularly memorable as it also provided our team the opportunity to visit Baotou, the world’s largest hub for rare earth production. Baotou’s industry is a cornerstone for the production and manufacturing of materials used in numerous advanced applications.

Our visit to the Baotou Research Institute of Rare Earths was an invaluable experience, offering us insights into the city’s pivotal role in the global rare earth industry. This visit aligned perfectly with our participation in THERMAG 2024, where we engaged with the latest advancements in caloric materials, prototypes, and their potential applications.

At the conference, the LAHDE team presented a diverse range of contributions, highlighting our cutting-edge work in the magnetocaloric field, including:

Prof. Dr. Andrej Kitanovski: Solid-State Energy Conversion: Applications and Perspectives (plenary talk)
Dr. Urban Tomc (Nada Petelin): Oscillating Gadolinium Thermal Switch
Assist. Prof. Dr. Katja Klinar: Navigating the Heat Maze: A Showcase Tutorial of TCCBuilder Software
Dr. Urban Tomc: High Frequency Magnetocaloric Cooling

We were thrilled to share our ideas and experiences with esteemed colleagues, scientists, and engineers from both academia and industry. The exchange of knowledge and the potential for future collaborations were among the many highlights of this event.

On a side note, we also took the opportunity to explore other wonders of China, such as the historic sites of Beijing and even climbed a section of the Great Wall.

We are also deeply honored to announce that LAHDE will be the host organizer for the next, 11th THERMAG conference in 2026, which will take place in Ljubljana, the beautiful capital of Slovenia. We look forward to welcoming you all!

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LAHDE’s Experience at Eurotherm 2024 Conference at Bled, Slovenia

admin — Wed, 26 Jun 2024 08:30:12 +0000

Our laboratory had the pleasure of attending the Eurotherm 2024 conference, held in the picturesque town of Bled, Slovenia from 9^th – 13^th June The conference was a fascinating experience, showcasing the latest advancement in thermal science and technology. We were thrilled to be part of such an esteemed gathering of experts and enthusiasts.

During the conference, we had the opportunity to meet and connect with new colleagues from various institutions and industries. These interactions were not only professionally enriching but also led to the formation of new friendships. The sense of community and shared passion for thermal sciences made the event truly special.

LAHDE laboratory participated in eight conference papers and their presentations:

Thermal control devices and thermal circuits (Katja Klinar, Andrej Kitanovski) – KEYNOTE LECTURE
Riding the thermal wave: A review of materials for thermal switches (Katja Klinar, Katja Vozel, Andrej Kitanovski)
Thermal control circuit modelling with TCCBuilder (Katja Vozel, Katja Klinar, Nada Petelin, Andrej Kitanovski)
Oscillating thermal switch using electrostatic forces (Nada Petelin, Borut Pečar, Danilo Vrtačnik, Urban Tomc, Andrej Kitanovski)
State of the art of heat pumps above 150 °C (Matevž Cimermančič, Katja Klinar, Andrej Kitanovski)
State of the art of micro vapour compression systems (Mihael Blatnik, Katja Klinar, Andrej Kitanovski)
Magnetocaloric cooling with fluidic thermal switches based on electrowetting effect (Urban Tomc, Blaž Velkavrh, Hana Uršič, Lukas Beyer, Jens Freudenberger, Klara Lünser, Enric Stern Taulats, Lluis Manosa, Andrej Kitanovski)
Fabrication of microfluidic thermal switches for magnetocaloric cooling applications (Blaž Velkavrh, Hana Uršič, Victor Regis, Matej Šadl, Bianka Colarič, Andrej Kitanovski, Urban Tomc)

One of the highlights of our participation was the student networking event organized by our section/group of thermal control elements. This event was great success, providing a platform for students to interact, share ideas, and build valuable connections for their future careers. The enthusiasm and energy at the networking event were palpable, and we were delighted to see such active engagement from the next generation of thermal scientists.

Overall, Eurotherm 2024 was an inspiring and memorable experience. We look forward to applying the insights gained and continuing the collaborations initiated at the conference and cannot wait for next Eurotherm conference in 2028, which is going to be held in Ghent, Belgium.

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MRS 2023 live again

lahde — Tue, 16 May 2023 10:48:23 +0000

After a period of virtual MRS meetings, the Spring Meeting 2023 was once again held in person. Around 2000 researchers, engineers and company representatives from all over the world gathered in San Francisco to present the results of their materials research and applications.

Also 6 members of LAHDE laboratory presented their results at the meeting:

– invited lecture held by prof. dr. Andrej Kitanovski (Thermal Management in Caloric Devices),

– assist. prof. dr. Jaka Tušek (Improving Efficiency of Elastocaloric Cycles by Applying Novel Thermodynamic Cycles and Proper Training Regime),

– dr. Urban Tomc (Digital Microfluidic Thermal Switch in Magnetocaloric Cooling),

– dr. Stefano Dall’Olio (Fatigue Resistant Elastocaloric Regenerative Cooler / Heat Pump Showing High Performance),

– dr. Katja Klinar (TCCbuilder: an Open-Source Tool for the Design and Evaluation of Thermal Circuits in Calorics and Other Applications),

– Nada Petelin (Thermal Switch Capacitor in a Magnetocaloric Device).

More info available here.

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Cool BatMan project as a part of the M-ERA.NET tender

lahde — Fri, 22 Jul 2022 05:06:38 +0000

The Laboratory for Refrigeration and District Energy (LAHDE) won the three-year Cool BatMan project as a part of the M-ERA.NET tender entitled Battery Thermal Management System Based on High Power Density Digital Microfluidic Magnetocaloric Cooling (Cool BatMan). It is a consortium of 4 quality institutions where LAHDE acts as a leading organization. In addition, it is also a gender-balanced consortium (two female researchers, two male researchers), which is one of the evaluation criteria in M-ERA and similar EU research platforms (H2020). The members of the consortium are:

Faculty of mechanical engineering, Laboratory for refrigeration and district energy (dr. Urban Tomc)
Jožef Stefan Institut, electronic ceramic department K5 (prof. dr. Hana Uršič Nemevšek)
Leibniz Institute for Solid State and Materials Research Dresden, (dr. Maria Krautz)
Universitat de Barcelona, Department de Fisica de la Materia Condensada, (prof. dr. Lluis Mañosa)

The goal of the Cool BatMan project is to establish a fundamental understanding of the dynamic thermal behavior of two physical phenomena coupled in a compact magnetocaloric cooling device. The magnetocaloric material (as a result, the magnetocaloric effect) will be combined with the phenomenon of electrowetting on the dielectric (i.e. digital microfluidics), which will create a unique principle of magnetocaloric cooling, which could be used as a thermal management system for batteries in the future.

In addition to coordinating the project, the Laboratory for Refrigeration and District Energy will be responsible for the electrohydrodynamic and thermomagnetic numerical modeling of the new proposed principle of magnetocaloric cooling with the implementation of digital microfluidics. The modeling results will provide important guidelines in the intermediate and final steps in fabrication of the “proof-of-concept” of an experimental cooling device, which will also finally be built and tested at the Faculty of Mechanical Engineering.

The European Commission is financing the M-ERA.NET network, which was established with the aim of connecting European research programs and their funding. It specifically focuses on innovations in the field of functional materials, thereby supporting the guidelines of the Green Deal.

Cool BatMan project work flow

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