Elastocaloric polymers
Lead Research Organisation:
University of Cambridge
Department Name: Materials Science & Metallurgy
Abstract
Caloric materials are a promising new group of materials with potential application in new
solid-state cooling technologies that are environment friendly and energy efficient. These
materials therefore constitute an alternative to the greenhouse gases that are currently used in
conventional vapour-compression refrigeration systems. Among the three types of caloric
material, elastocaloric materials driven by mechanical stress promise extremely large (giant)
thermal changes under low mechanical loads that are easy and inexpensive to generate.
My PhD project is aimed at studying elastocaloric effects in elastic polymers (i.e. elastomers),
as they promise giant thermal changes driven by small mechanical loads. I evaluate
elastocaloric effects via thermodynamic analysis of temperature-dependent stress-strain
measurements, and measure them directly using a state-of-the-art infra-red camera, with high
spatial and time resolution. I also develop numerical computational models in order to gain
insight into the performance of elastocaloric materials, and ultimately design affordable and
efficient cooling devices.
solid-state cooling technologies that are environment friendly and energy efficient. These
materials therefore constitute an alternative to the greenhouse gases that are currently used in
conventional vapour-compression refrigeration systems. Among the three types of caloric
material, elastocaloric materials driven by mechanical stress promise extremely large (giant)
thermal changes under low mechanical loads that are easy and inexpensive to generate.
My PhD project is aimed at studying elastocaloric effects in elastic polymers (i.e. elastomers),
as they promise giant thermal changes driven by small mechanical loads. I evaluate
elastocaloric effects via thermodynamic analysis of temperature-dependent stress-strain
measurements, and measure them directly using a state-of-the-art infra-red camera, with high
spatial and time resolution. I also develop numerical computational models in order to gain
insight into the performance of elastocaloric materials, and ultimately design affordable and
efficient cooling devices.
Organisations
People |
ORCID iD |
| Xavier Moya (Primary Supervisor) | |
| Michal Kaminski (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509620/1 | 01/10/2016 | 30/09/2022 | |||
| 1939499 | Studentship | EP/N509620/1 | 01/10/2017 | 30/09/2021 | Michal Kaminski |
| Description | For my research project, I study the elastocaloric performance of elastic polymers that promise future environmentally friendly refrigeration. I combine experimental measurements and computational modelling in order to understand fully the elastocaloric properties of the investigated materials. My main achievements to date are: - I found giant adiabatic changes in temperature of ~7.5 K on loading, and of ~ -9 K on unloading, near room temperature. These temperature changes compare well with those observed in state-of-the-art elastocaloric metals, but require two order of magnitude smaller driving stress. - Using computational models, I explained the previously unexpected difference seen in the recorded temperature change on loading and unloading. This difference arises due to changes in the degree of crystallinity at constant strain, and I confirmed my findings via mechanical testing and Raman spectroscopy. - I also found that pre-straining samples by 100% prior to any elastocaloric cycling improved their fatigue life without compromising the elastocaloric response. |
| Exploitation Route | Cooling technologies for refrigeration and air-conditioning contribute largely to the global energy usage. For over 100 years, energy-inefficient vapour-compression devices have been the most popular method for cooling. Apart from their relatively low energy efficiency, vapour-compression systems also constitute a serious threat for the environment because they use fluid refrigerants that are harmful greenhouse gases. My findings could lead to new solid-state cooling technologies that are both environmentally friendly and energy efficient. |
| Sectors | Aerospace, Defence and Marine,Agriculture, Food and Drink,Energy,Environment,Transport |