Projects / Programmes
Electrocaloric elements for active cooling of electronic circuits
| Code |
Science |
Field |
Subfield |
| 2.09.01 |
Engineering sciences and technologies |
Electronic components and technologies |
Materials for electronic components |
| Code |
Science |
Field |
| T153 |
Technological sciences |
Ceramic materials and powders |
| Code |
Science |
Field |
| 2.05 |
Engineering and Technology |
Materials engineering |
Electrocaloric, cooling, relaxor ferroelectric, PMN-PT, multilayer, thermal switch, radiation hardness
Researchers (23)
Organisations (2)
Abstract
Increasing needs of society for cooling have become a global priority, ever larger amounts of energy are needed for cooling. This includes also electronic components and devices, where faster operation and miniaturisation are general trends, but that also means that more heat is generated on progressively smaller volumes. A solution to such problems may be the innovative use of relaxor ferroelectric ceramic materials in cooling applications, namely by exploiting the electrocaloric (EC) effect. The latter is defined as a temperature change induced in a polar material by an electric field.
In this project we will study the feasibility of relaxor ferroelectric ceramic EC elements in active cooling of electronic components for niche applications such as medical radio-therapy, nuclear reactors and space technologies. Ferroelectric-oxide devices have been previously tested for operation in locations with exposure to ionizing radiation, but the influence of the latter on the EC effect has not been experimentally assessed yet. The benefits of EC cooling in electronics, such as being solid-state (no refrigerant gases), compactness, high efficiency, fast response, triggering by an electrical input, have been proposed theoretically and in reviews. Our ambition is to design and fabricate a miniature proof-of-concept EC-cooler, consisting of EC multilayer elements, combined with thermal switches to control the heat-transfer.
Specifically, i) we will design relaxor ferroelectric ceramic materials with a maximized EC effect in a given operational temperature range, ii) we will study the effect of ionizing irradiation on the EC effect and if needed adjust the composition and/or microstructure of the EC material, iii) as proof of concept we will fabricate a microscale cooler consisting of EC multilayer elements and thermal switches. The project is organized into three interrelated research Work Packages (WPs) and a project-management WP.
The objective of WP1: EC materials engineering is to design relaxor ferroelectric ceramic materials with a maximized EC effect in a given operational temperature range, mainly around/slightly above room temperature. We note that one of the best performing inorganic EC materials, 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 (PMN-10PT) exhibits the largest EC effect at electric fields of about 100 kV/cm at about 100 oC. By donor and/or isovalent doping we plan to down-shift the temperature-interval of the maximum EC effect in PMN-10PT close to room temperature.
In WP2: Irradiation study the influence of gamma and neutron irradiation on the EC effect of materials selected in WP1 will be evaluated. The samples will be exposed to progressively larger doses of neutron and gamma irradiation at TRIGA Mark II reactor (JSI) until changes in the microstructure and EC response of the irradiated materials are detected. In case of a major decrease of the EC effect, and with support of modelling different approaches to alleviate it are planned, including changes in the defect chemistry and/or microstructural details of the material.
WP3: Demo EC-cooler will include three tasks. EC multilayer elements consisting of materials selected in WP1 and tested in WP2 will be fabricated by tape-casting technology. Thermal switches will be used to control the heat-transfer between the EC elements and the heat sink/source. Different solutions, including posistors, materials exhibiting triboelectric effect, and thermoelastic coatings, will be numerically modelled and experimentally tested. Comparison of test results will allow us to select an optimum material and technology for the switch. A miniature EC-cooler will be designed, fabricated and tested as proof of concept.
Significance for science
Caloric cooling technologies are becoming a serious alternative to existing refrigeration technologies, such as vapour compression. Caloric effects: electrocaloric (EC), magnetocaloric and mechanocaloric, are moving towards the application level, and this is especially evident for the effects with long histories, such as the magnetocaloric effect.
One of the steps towards EC cooling application includes increasing EC temperature changes of the EC materials within the operational temperature range. There is an urgent need to develop materials which will be able to exhibit high EC temperature changes at moderate electric field amplitudes. Presently the maximum EC temperature changes of one of the best performing EC ceramic materials, PMN-10PT, are a few K at/above 100 oC. By introducing selected dopants we plan to down-shift the maximum EC effect closer to room temperature.
The advantage of the EC effect is in the stimulus needed to obtain it – voltage is more readily available and it does not require large volumes as magnets do; furthermore, voltage is inherently present or available in every electronic component. An EC cooling element is solid-state, without moving parts and thus compatible with the trend of miniaturisation in electronics. In parallel we will study new approaches in the heat transfer with the focus on thermal switches.
Stability of operation of electronic components and devices is especially important in medical radio-therapy and in space technologies. We plan to study the effect of ionizing radiation on the EC effect, and as there are no published reports on such experimental studies, our results will contribute to opening new areas of exciting applications.
The market of caloric materials and devices is still to be created, making pressure on basic research. We note that our proposal fits well in the activities of Slovenian Smart Specialization Strategy, namely Strategic research and innovation partnerships Factories of the Future and Health-Medicine.
In Slovenia we have world-leading research groups on caloric materials and technologies involved in the proposed project and connected with Slovenian industry. The house-appliances company Gorenje took over the patent based on the EC cooling device working on the principle of active electrocaloric regeneration (the project applicant is one of the inventors together with colleagues from JSI and Faculty of Mechanical Engineering). KEKO Equipment is producer of equipment for production of multilayer elements.
After the development of a proof-of-concept EC-cooler (which is the goal of this project), the results will be presented to our industrial partners in the frame of the Slovenian Smart Specialization Strategy activities. We are aiming to continue research on this topic, therefore the project results are expected to have long-term consequences not only in research but also in the industrial sector. Therefore, this research will continue also after the project closure.
Significance for the country
Caloric cooling technologies are becoming a serious alternative to existing refrigeration technologies, such as vapour compression. Caloric effects: electrocaloric (EC), magnetocaloric and mechanocaloric, are moving towards the application level, and this is especially evident for the effects with long histories, such as the magnetocaloric effect.
One of the steps towards EC cooling application includes increasing EC temperature changes of the EC materials within the operational temperature range. There is an urgent need to develop materials which will be able to exhibit high EC temperature changes at moderate electric field amplitudes. Presently the maximum EC temperature changes of one of the best performing EC ceramic materials, PMN-10PT, are a few K at/above 100 oC. By introducing selected dopants we plan to down-shift the maximum EC effect closer to room temperature.
The advantage of the EC effect is in the stimulus needed to obtain it – voltage is more readily available and it does not require large volumes as magnets do; furthermore, voltage is inherently present or available in every electronic component. An EC cooling element is solid-state, without moving parts and thus compatible with the trend of miniaturisation in electronics. In parallel we will study new approaches in the heat transfer with the focus on thermal switches.
Stability of operation of electronic components and devices is especially important in medical radio-therapy and in space technologies. We plan to study the effect of ionizing radiation on the EC effect, and as there are no published reports on such experimental studies, our results will contribute to opening new areas of exciting applications.
The market of caloric materials and devices is still to be created, making pressure on basic research. We note that our proposal fits well in the activities of Slovenian Smart Specialization Strategy, namely Strategic research and innovation partnerships Factories of the Future and Health-Medicine.
In Slovenia we have world-leading research groups on caloric materials and technologies involved in the proposed project and connected with Slovenian industry. The house-appliances company Gorenje took over the patent based on the EC cooling device working on the principle of active electrocaloric regeneration (the project applicant is one of the inventors together with colleagues from JSI and Faculty of Mechanical Engineering). KEKO Equipment is producer of equipment for production of multilayer elements.
After the development of a proof-of-concept EC-cooler (which is the goal of this project), the results will be presented to our industrial partners in the frame of the Slovenian Smart Specialization Strategy activities. We are aiming to continue research on this topic, therefore the project results are expected to have long-term consequences not only in research but also in the industrial sector. Therefore, this research will continue also after the project closure.
Most important scientific results
Interim report
Most important socioeconomically and culturally relevant results
Interim report
