Qiming Zhang

Qiming Zhang

Polar-dielectrics with Giant Electrocaloric Effect and Their Related Cooling Devices


The direct and efficient coupling between the electric signals and the elastic, thermal, optical and magnetic signals in ferroelectric based electroactive polymers makes them attractive for exploiting a broad range of cross-coupling phenomena and applications which have great promise for new device technologies.  This talk will present the recent advances in developing electroactive polymers which may provide alternative cooling technology to replace the century old vapor compression cycle (VCC) based cooling which employs strong greenhouse gases as the refrigerants. Electrocaloric effect (ECE), which is the temperature and entropy change of insulating dielectric materials under electric fields, is attractive to realize efficient cooling devices.  However, the relatively small ECE observed in dielectrics in the last century make it unimpressive for any practical applications.  By making use of phase transitions and the high dipolar entropy in these polymers in the dipolar disordered state we demonstrated that a giant ECE can be achieved in a class of ferroelctric polymers. Moreover, by employing defects modifications to convert the normal ferroelectric into a ferroelectric relaxor a large ECE over a broad temperature range about room temperature can be obtained.  This talk will also discuss considerations on and present recent works in using nanocomposites to further enhancing the ECE beyond the pure relaxor polymers and on the giant ECE in a class of dielectric liquid. The works related to developing the chip-scale EC cooling devices, exploiting the newly discovered large ECE in ferroelectric polymers, will also be presented.


to the European Conference on Materials and Technologies for Sustainable Growth website.

ECo MaTech will be held in Bled (Slovenia) from 19th to 21st of September 2013.

Eco MaTech is the third edition of a conference that started in 2009. The aim of ECo MaTech is to gather representatives of academic and R&D institutions, industry, governmental agencies and civil society to:

- present their work, ideas and products, 
- increase fruitful exhanges between all the actors involved in sustainable growth technologies, 
- increase the networking with sustainable growth professionals, 
- establish a general discussion platform on sustainable growth.


The conference excursion will take you to the Alpine lake Bohinj (http://www.bohinj.si/en) and waterfall Savica (http://www.burger.si/Slapovi/Bohinj/Savica/uvod_ENG.html).
A farewell party will follow the lake trip by a boat. Comfortable shoes are recommended.

Only cash is exepted for on-site payment.

The poster panels are 1m wide and 2m high. The standrad A0 size posters are recommended (841mm:1189mm).