报 告 人:Qing Wang 教授 Pennsylvania State University

报告时间:2024年12月15日 周日 上午8:00-10:00

地 点:三一大楼 603

报告摘要:

Ferroelectric polymers represented by poly(vinylidene fluoride) and its copolymers enable thedevelopment of flexible piezoelectric devices for a wide range of applications, including wearableelectronics, human-machine interfaces, energy harvesting, soft robotics, and ultrasonic imagingThis talk will describe our recent efforts on the improvements of piezoelectric coefficients andelastic energy densities of PVDF-based ferroelectric polymers and composites. Inspired by themorphotropic phase boundary (MPB), a critical concept in the design of high-performancepiezoelectric ceramics, we establish the coexistence regions of the competing ferroelectric andrelaxor properties in the P(VDF-TrFE) copolymers and reveal the crucial role of chain tacticity indriving the formation of the transition region. The copolymer with the morphotropic compositionexhibits state-of-the-art piezoelectric coefficients. We employ an electro-thermal approach todrive the ferroelectric phase transition in PVDF-based percolative polymer nanocomposites. Theactuators based on electro-thermal actuation outpertor cuirent polyer-based actuators in termsof concurrently enhanced actuation strain and elastic enerey density that are triggered at a muchlower electric field, In this regard, electro-thermal actuatorsbased on ferroelectric polyme1nanocomposites can bridge the gap between ferroelectric polymers and piezoelectric ceramicsThis talk will discuss fundamental insights into the structural mechanisms that controlDiezoelectricity and actuations in ferroelectric polymers.

报告人简介:

Prof, Oing Wang received his Ph.D. in Chemistry from the University of Chicago in 2000Prior to ioining the faculty at Penn State in 2002. he was a postdoctoral researcher at CornelUniversity. Among other awards, he has received the National Science Foundation CAREERAward, Rustum and Della Roy Innovation in Materials Research Award and Penn State FacultScholar ledal in Engineering, His research interests include the development of ferroelectricpolymers, electroactive polymers, dielectric polymers and nanocomposites for energy harvestingand storage. Prof. Wang is a Fellow of AAAS and IEEE.