Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 2, 2019
Previous Article Next Article

Designing soft pyroelectric and electrocaloric materials using electrets

Author affiliations

Abstract

A temperature variation can electrically polarize a pyroelectric material. In its converse manifestation, the electrocaloric effect entails a change in temperature due to the application of an electric field. These phenomena have wide applications ranging from infrared detection sensors and solid-state refrigeration to energy harvesting. However, the pyroelectric–electrocaloric effect is typically observed in certain classes of hard, brittle crystalline materials that must satisfy a stringent set of lattice symmetry conditions. Some limited experiments have however demonstrated that embedding immobile charges and dipoles in soft foams (thus creating an electret state) may lead to a pyroelectric-like response as well as large deformations desired from soft matter. In this work, we develop a systematic theory for coupled electrical, thermal and mechanical responses of soft electrets. Using simple illustrative examples, we derive closed-form explicit expressions for the pyroelectric and electrocaloric coefficients of electrets. While pyroelectricity in electrets has been noted before, our derived expressions provide a clear quantitative basis to interpret (and eventually design) this effect as well as insights into how the geometrically nonlinear deformation and Maxwell stress give rise to its emergence. We present conditions to obtain a larger pyroelectric and electrocaloric response. In particular, the electrocaloric effect is predicted for the first time in such materials and we show that a proper design and a reasonable choice of materials can lead to a temperature reduction of as much as 1.5 K under the application of electrical fields of 10 MV cm−1.

Graphical abstract: Designing soft pyroelectric and electrocaloric materials using electrets

Back to tab navigation

Article information


Submitted
02 Oct 2018
Accepted
05 Nov 2018
First published
09 Nov 2018

Soft Matter, 2019,15, 262-277
Article type
Paper
Author version available

Designing soft pyroelectric and electrocaloric materials using electrets

F. Darbaniyan, K. Dayal, L. Liu and P. Sharma, Soft Matter, 2019, 15, 262
DOI: 10.1039/C8SM02003E

Social activity

Search articles by author

Spotlight

Advertisements