Hoejin Kim

Mr. Hoejin Kim


Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
13 July 2017 in Smart Materials and Structures
Verified
Journal Article
Closed access
PDF file
HKHoejin Kim
Hoejin Kim
FTFernando Torres
Fernando Torres
YWYanyu Wu
Yanyu Wu
DVDino Villagran
Dino Villagran
YLYirong Lin
Yirong Lin
TTTzu-Liang (Bill) Tseng
Tzu-Liang (Bill) Tseng
This paper presents a novel process to fabricate piezoelectric films from polyvinylidene fluoride (PVDF) polymer using integrated fused deposition modeling (FDM) 3D printing and corona poling technique. Corona poling is one of many effective poling processes that has received attention to activate PVDF as a piezoelectric responsive material. The corona poling process occurs when a PVDF polymer is exposed to a high electric field created and controlled through an electrically charged needle and a grid electrode under heating environment. FDM 3D printing has seen extensive progress in fabricating thermoplastic materials and structures, including PVDF. However, post processing techniques such as poling is needed to align the dipoles in order to gain piezoelectric properties. To further simplify the piezoelectric sensors and structures fabrication process, this paper proposes an integrated 3D printing process with corona poling to fabricate piezoelectric PVDF sensors without post poling process. This proposed process, named ‘Integrated 3D Printing and Corona poling process’ (IPC), uses the 3D printer’s nozzle and heating bed as anode and cathode, respectively, to create poling electric fields in a controlled heating environment. The nozzle travels along the programmed path with fixed distance between nozzle tip and sample’s top surface. Simultaneously, the electric field between the nozzle and bottom heating pad promotes the alignment of dipole moment of PVDF molecular chains. The crystalline phase transformation and output current generated by printed samples under different electric fields in this process were characterized by a Fourier transform infrared spectroscopy and through fatigue load frame. It is demonstrated that piezoelectric PVDF films with enhanced β -phase percentage can be fabricated using the IPC process. In addition, mechanical properties of printed PVDF was investigated by tensile testing. It is expected to expand the use of additive manufacturing to fabricate piezoelectric PVDF-based devices for applications such as sensing and energy harvesting.

23 August 2017 in Macromolecular Materials and Engineering
Verified
Journal Article
Closed access
PDF file
HKHoejin Kim
Hoejin Kim
FTFernando Torres
Fernando Torres
DVDino Villagran
Dino Villagran
CSCalvin Stewart
Calvin Stewart
YLYirong Lin
Yirong Lin
TTTzu‐Liang Bill Tseng
Tzu‐Liang Bill Tseng

1 August 2018 in Journal of Environmental Chemical Engineering
Verified
Journal Article
Closed access
MAMd. Ariful Ahsan
Md. Ariful Ahsan
TITariqul Islam
Tariqul Islam
CHCesar Hernandez
Cesar Hernandez
HKHoejin Kim
Hoejin Kim
YLYirong Lin
Yirong Lin
JNJuan C. Noveron
Juan C. Noveron

1 December 2017 in MRS Communications
Verified
Journal Article
Closed access
PDF file
HKHoejin Kim
Hoejin Kim
TITariqul Islam
Tariqul Islam
IDIslam Md Didarul
Islam Md Didarul
LCLuis A. Chavez
Luis A. Chavez
CRCarlos A. Garcia Rosales
Carlos A. Garcia Rosales
YLYirong Lin
Yirong Lin

1 June 2018 in Materials Research Express
Verified
Journal Article
Closed access
CRCarlos A Garcia Rosales
Carlos A Garcia Rosales
MDMario F Garcia Duarte
Mario F Garcia Duarte
HKHoejin Kim
Hoejin Kim
LCLuis A. Chavez
Luis A. Chavez
DHDeidra Hodges
Deidra Hodges
TTTzu-Liang (Bill) Tseng
Tzu-Liang (Bill) Tseng

20 September 2019 in MRS Communications
Verified
Journal Article
Closed access
PDF file
HKHoejin Kim
Hoejin Kim
LMLuis Carlos Delfin Manriquez
Luis Carlos Delfin Manriquez
TITariqul Islam
Tariqul Islam
LCLuis A. Chavez
Luis A. Chavez
JRJaime E. Regis
Jaime E. Regis
YLYirong Lin
Yirong Lin