Special Seminar: Qiming Zhang

Title:

Fluoropolymer Ferroelectrics For Energy Conversions

Abstract:

Polymeric ferroelectrics are unique for their high pliability, easy fabrication into complicated shapes, and mechanical robustness along with a polar active nature. In the past few years, polymer ferroelectrics have exhibited marked improvements in the electromechanical coupling efficiency, electrostrictive strain, electrocaloric heat-pumping capability, which has significantly boosted the development of practical applications based on these polar soft materials. For the first time, the piezoelectric and electromechanical coupling factors of fluorinated alkyne-modified relaxor ferroelectric tetrapolymers have surpassed those of PZT piezoceramics, the presently most widely used piezoceramics in the world. Coupled with the progressive large electrostrictive strain under low electrical fields, this advancement represents a step forward in developing efficient wearable sensory and haptic devices and soft robots. Additionally, the advances in ferroelectric-based electrocaloric polymers have led to large electrocaloric cooling under ultralow electric fields. These ferroelectric polymers can offer customized, energy-efficient solutions to curb the CO₂ emissions introduced by the current commercial heat pumps, air conditioners (ACs) and refrigerators, which are responsible for 60% of building emissions.

Bio:

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 invented the relaxor ferroelectric polymers which possess record high dielectric permittivity and polymer thin film actuators with giant electroactuation and ultra-high electromechanical coupling factor. The relaxor polymers have been commercialized by Arkema. He founded a high-tech startup, Novasentis, Inc. (acquired by KEMET in 2019), in commercializing the relaxor polymer thin film actuators and sensors, as well their haptic, wearable, microfluid devices. The company was listed by The Science Coalition in 2013 as one of 100 successful startups created from federally funded university research (Sparking Economic Growth 2.0, Oct. 2013). Since the late 2000s, his group has developed ferroelectric polymers and ceramics with large electrocaloric effect, creating unique opportunity for solid state cooling with high efficiency and zero green greenhouse gas emission. Exploiting the unique features of ECE, his group has invented several solid-state EC cooling devices which have the promise for compact and distributed high efficiency EC coolers. He is a Fellow of IEEE, APS, and NAI.