@article{qin_wei_dong_lee_2017, title={Direct Printing and Electrical Characterization of Conductive Micro-Silver Tracks by Alternating Current-Pulse Modulated Electrohydrodynamic Jet Printing}, volume={139}, ISSN={["1528-8935"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000393881400008&KeyUID=WOS:000393881400008}, DOI={10.1115/1.4033903}, abstractNote={In this paper, a rapid prototyping method for fabrication of highly conductive micropatterns on insulating substrates was developed and evaluated. Sub-20 μm microstructures were printed on flexible insulating substrates using alternating current (AC) modulated electrohydrodynamic jet (e-jet) printing. The presented technique resolved the challenge of current rapid prototyping methods in terms of limited resolution and conductivity for microelectronic components for flexible electronics. Significant variables of fabrication process, including voltage, plotting speeds, curing temperature, and multilayer effect, were investigated to achieve reliable printing of silver tracks. Sub-20 μm silver tracks were successfully fabricated with resistivity about three times than bulk silver on flexible substrates, which indicates the potential applications of electrohydrodynamic printing in flexible electronics and medical applications, such as lab-on-chip systems.}, number={2}, journal={JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME}, author={Qin, Hantang and Wei, Chuang and Dong, Jingyan and Lee, Yuan-Shin}, year={2017}, month={Feb} }
 @article{wei_qin_chiu_lee_dong_2015, title={Drop-on-demand E-jet printing of continuous interconnects with AC-pulse modulation on highly insulating substrates}, volume={37}, ISSN={["1878-6642"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000367698200008&KeyUID=WOS:000367698200008}, DOI={10.1016/j.jmsy.2014.07.005}, abstractNote={In this paper, we present a novel AC-pulse modulated electrohydrodynamic (EHD) jet printing technology that enables high resolution fabrication of electrical features and interconnects using the silver nanoink on highly insulating substrates. In traditional EHD jet printing, the remained charge of the printed droplets changes the electrostatic field distribution and interrupts the follow-on printing behavior, especially for highly insulating substrates having a slow charge decay rate. In this paper, a modulated AC-pulsed voltage was used for the EHD jet printing process that can alternate the charge polarity of the consequent droplets to neutralize the residue charge on the substrate. The effect of the residue charge is minimized, which enables high resolution printing of continuous patterns. With three printing parameters (e.g. pulse frequency, voltage, and duration), the EHD jet printing speed and droplet size can be controlled independently. We demonstrated that AC-pulse modulated EHD jet printing can overcome the charge accumulation challenge on highly insulating substrates, and investigated the variables of fabrication process to achieve reliable jet printing of conductive silver tracks.}, journal={JOURNAL OF MANUFACTURING SYSTEMS}, author={Wei, Chuang and Qin, Hantang and Chiu, Chia-Pin and Lee, Yuan-Shin and Dong, Jingyan}, year={2015}, month={Oct}, pages={505–510} }
 @article{han_wei_dong_2015, title={Droplet formation and settlement of phase-change ink in high resolution electrohydrodynamic (EHD) 3D printing}, volume={20}, ISSN={["2212-4616"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000367634700007&KeyUID=WOS:000367634700007}, DOI={10.1016/j.jmapro.2015.06.019}, abstractNote={This paper presents a modeling framework to model the droplet formation and settlement on substrate of phase-change ink in high resolution electrohydrodynamic (EHD) printing process, which can successfully produce sub 10-μm droplet footprints and 3D microstructure. We have used Finite Element Analysis (FEA) to develop the model for droplet formation and droplet settlement. Two important competitive forces in EHD printing, electrostatic force and surface tension force are modeled by FEA. The droplet size is obtained by balancing the electrostatic force and surface tension of the pending droplets at the tip of the meniscus under different printing conditions. With the results from FEA analysis about the charge on a droplet and electrostatic field distribution, the droplets in-flight velocity and impact velocity on the substrate are derived numerically. With the derived impact velocity, the droplet spreading and settlement on the substrate is also modeled by FEA. The results from FEA models are compared with the experimental measured droplet dimensions at different process conditions to validate the developed model, which demonstrate very good agreement between the experimental results and model prediction. We have successfully applied EHD printing process for phase-change wax material, which is widely used in 3D printing or additive manufacturing for supporting and model material, to achieve high resolution sub 10-μm 3D structures.}, journal={JOURNAL OF MANUFACTURING PROCESSES}, author={Han, Yiwei and Wei, Chuang and Dong, Jingyan}, year={2015}, month={Oct}, pages={485–491} }
 @article{qin_wei_dong_lee_2014, title={DIRECT FABRICATION OF HIGHLY CONDUCTIVE MICRO SILVER TRACKS USING ELECTROHYDRODYNAMIC JET PRINTING FOR SUB-20 mu M MICRO-MANUFACTURING}, volume={2}, ISBN={["978-0-7918-4581-3"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84908429027&partnerID=MN8TOARS}, DOI={10.1115/msec2014-4163}, abstractNote={This paper presents a direct fabrication method of highly conductive silver tracks with sub-20 μm microstructures on glass substrate by using electrohydrodynamic jet printing (EHDJP) with alternative current (AC) voltage. Traditional ink jet printing fabrication approaches are limited in the achievable resolution. EHDJP has been used in directly printing by generating a fine jet through a large electrical potential between nozzle and substrate. When charge accumulates on the ink meniscus at the nozzle, a fine jet down to nano scale can be generated. In the paper, we successfully applied EHDJP for fabrication of highly conductive silver tracks using AC voltage. It was the first time that sub-20 μm silver tracks were demonstrated and printed with resistivity about 3.16 times than bulk silver. The variables of fabrication process were investigated to achieve reliable jet printing of conductive silver tracks. The topography of printed tracks was characterized and verified in the study. The presented technique can be used for micro-manufacturing of three-dimensional microstructures and biomedical device fabrications.}, journal={PROCEEDINGS OF THE ASME 9TH INTERNATIONAL MANUFACTURING SCIENCE AND ENGINEERING CONFERENCE, 2014, VOL 2}, author={Qin, Hantang and Wei, Chuang and Dong, Jingyan and Lee, Yuan-Shin}, year={2014} }
 @article{wei_dong_2014, title={Development and modeling of melt electrohydrodynamic-jet printing of phase-change inks for high-resolution additive manufacturing}, volume={136}, number={6}, journal={Journal of Manufacturing Science and Engineering}, author={Wei, C. and Dong, J. Y.}, year={2014} }
 @article{wei_qin_ramirez-iglesias_chiu_lee_dong_2014, title={High-resolution ac-pulse modulated electrohydrodynamic jet printing on highly insulating substrates}, volume={24}, ISSN={["1361-6439"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84897548526&partnerID=MN8TOARS}, DOI={10.1088/0960-1317/24/4/045010}, abstractNote={This paper presents a new high-resolution ac-pulse modulated electrohydrodynamic (EHD)-jet printing technology on highly insulating substrates for drop-on-demand fabrication of electrical features and interconnects using silver nanoink. In traditional EHD-jet printing, the remained charge of the printed droplets changes the electrostatic field distribution and interrupts the follow-on printing behavior, especially for highly insulating substrates which have slow charge decay rates. The residue charge makes the control of EHD-jet printing very challenging for high-resolution continuous features. In this paper, by using modulated ac-pulsed voltage, the EHD-jet printing process switches the charge polarity of the consequent droplets to neutralize the charge on the substrate. The effect of the residue charge is minimized, which enables high-resolution printing of continuous patterns. Moreover, by modulating the pulse frequency, voltage, and duration, the EHD-jet printing behavior can be controlled with respect to printing speed/frequency and droplet size. Printing frequency is directly controlled by the pulse frequency, and the droplet dimension is controlled by the voltage and the duration of the pulse. We demonstrated that ac-pulse modulated EHD-jet printing can overcome the long-predicated charge accumulation problem on highly insulating substrates, and potentially be applied to many flexible electronics applications.}, number={4}, journal={JOURNAL OF MICROMECHANICS AND MICROENGINEERING}, author={Wei, Chuang and Qin, Hantang and Ramirez-Iglesias, Nakaira A. and Chiu, Chia-Pin and Lee, Yuan-shin and Dong, Jingyan}, year={2014}, month={Apr} }
 @article{wei_dong_2014, title={Hybrid hierarchical fabrication of three-dimensional scaffolds}, volume={16}, ISSN={["2212-4616"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000349566600012&KeyUID=WOS:000349566600012}, DOI={10.1016/j.jmapro.2013.10.003}, abstractNote={Three-dimensional (3D) porous structures facilitating cell attachment, growth, and proliferation is critical to tissue engineering applications. Traditional solid freeform fabrication (SFF) methods have limited capabilities in the fabrication of high resolution micro-scale features to implement advanced biomedical functions. In this work, we present a hybrid scaffold fabrication approach by integrating electrohydrodynamic (EHD) printing technology with extrusion deposition together to fabricate hierarchical 3D scaffolds with well controlled structures at both macro and micro scale. We developed a hybrid fabrication platform and a robust fabrication process to achieve 3D hierarchical structures. The melting extrusion by pneumatic pressure was used to fabricate 3D scaffolds with filaments dimension of hundreds of microns using thermoplastic biopolymer polycaprolactone (PCL). An electrohydrodynamic (EHD) melt jet plotting process was developed to fabricate micro-scale features on the scaffolds with sub-10 μm resolution, which has great potential in advanced biomedical applications, such as cell alignment and cell guidance.}, number={2}, journal={JOURNAL OF MANUFACTURING PROCESSES}, author={Wei, Chuang and Dong, Jingyan}, year={2014}, month={Apr}, pages={257–263} }
 @article{wei_dong_2013, title={Direct fabrication of high-resolution three-dimensional polymeric scaffolds using electrohydrodynamic hot jet plotting}, volume={23}, number={2}, journal={Journal of Micromechanics and Microengineering}, author={Wei, C. and Dong, J. Y.}, year={2013} }
 @inproceedings{wei_sonawane_cai_wang_dong_2012, title={Direct-deposition and multiple materials integration of tissue engineering scaffolds}, booktitle={Proceedings of the ASME International Mechanical Engineering Congress and Exposition 2010, vol 3, pts A and B}, author={Wei, C. and Sonawane, B. and Cai, L. and Wang, S. F. and Dong, J. Y.}, year={2012}, pages={1083–1088} }
 @article{wei_cai_sonawane_wang_dong_2012, title={High-precision flexible fabrication of tissue engineering scaffolds using distinct polymers}, volume={4}, number={2}, journal={Biofabrication}, author={Wei, C. and Cai, L. and Sonawane, B. and Wang, S. F. and Dong, J. Y.}, year={2012} }