Advanced Ferroelectric Polymers for Wearables - Prof Qiming ZHANG

Prof. Qiming ZHANG
Distinguished Professor of Electrical Engineering
Pennsylvania State University
Qiming Zhang is a Distinguished Professor of Engineering at the Pennsylvania State University, USA. His research covers electronic materials, especially polymers and composites, and their devices and applications. Zhang developed the relaxor ferroelectric polymers which possess record high dielectric permittivity at room temperature and polymer thin film actuators with giant electroactuation. The relaxor polymers have been commercialized by Arkema. He founded a high-tech startup with $20 million US dollars VC investments, Novasentis, Inc. (was acquired by KEMET in 2019), in commercializing the relaxor polymer thin film actuators and sensors, as well their haptic, wearable, microfluid devices. In 2008, he developed ferroelectric polymers with giant electrocaloric effect, creating unique opportunity for solid state cooling with high efficiency and zero green greenhouse gas emission. More recently, his group developed polymer dilute nanocomposites in which ultralow volume loading of nanofillers, through interface effects, generate marked enhancement in dielectric constant and breakdown strength, creating a totally new avenue, which is low cost and highly scalable, for developing polymer dielectric capacitors of high energy density and operating temperature. He authored more than 470 journal publications and has 15 patents. He is a Fellow of IEEE and APS.
Advanced Ferroelectric Polymers for Wearables
Abstract
Owing to their high pliability, easy fabrication into complicated shapes, and light weight, ferroelectric polymers have been widely used in wearables such as sensors, transducers, and haptics. However, the low electromechanical coupling and low piezoelectric effect, compared with their inorganic counterparts, severely limit their performance and usefulness in these applications. This talk will present recent advances in ferroelectric polymers that exhibit the electromechanical coupling and piezo-coefficient higher than the most widely used piezo-PZT ceramics. Such a high EM performance, in addition to improve the performance of the current wearables, has the promise of realizing high efficiency wearable energy harvesting. Wearable cooling (and thermal management) is another area of great needs. Active cooling with high energy efficiency has several advantages compared with passive wearable cooling. Ferroelectric polymers that generate large electrocaloric (EC) temperature change at ultralow electric fields may provide an attractive solution for active wearable cooling, which is voltage driven, compressor-free (low noise), compact size and light weight, and possesses high efficiency. This talk will present recent advances in EC polymer cooling devices and breakthroughs of EC polymers and polymer nanocomposites in generating large EC temperature change at very low electric fields.