The Woodruff School

SUMMARY

Inkjet deposition enables more efficient, economic, scalable manufacturing for a wide variety of materials than other traditional additive techniques. The impact of droplets onto a substrate is critical for accuracy control and optimization of the droplet deposition process. A full understanding of droplets deposition process is critical to build an ink-jet printer to produce good quality parts with good accuracy control, to save manufacturing time and to reduce the complexity of the machine. This research is proposed to help understand the physics behind the polymeric droplet deposition process so that the deposition process can be well controlled to produce desired shape, which includes droplet impingement dynamics, polymerization kinetics and the coupling effects between them. There are many critical issues involved in this complicated droplet deposition process and this research shall seek to address some of the most research issues to help understand the droplet deposition process. The following research questions have been identified to be answered by this research:

1. How to characterize the droplet shape so that more information of the physics of the droplet impingement can be contained in this metric?
2. Which parameters have the most significant influence on the droplet shape evolution and how do these parameters affect the best achievable shape and the timing of it?
3. How to build a numerical model that can simulate the droplet impingement dynamics more efficiently than the conventional commercially available simulation software packages with adequate accuracy to enable 3-D simulation of the droplet impingement dynamics and make it possible to study the droplets interaction dynamics?
4. How to numerically model the coupling effects between the droplet impingement dynamics and polymerization dynamics to help understand this process?

The intellectual merit of this research lies in developing scientific method and research tool by answering the above four critical research questions to help develop a strong scientific understanding of the physics behind droplets impingement dynamics and the polymerization kinetics and the coupling effects between them. This knowledge will help us decide the deposition parameters (including both impingement parameters and polymerization parameters) and control the deposition process to build the desired geometry.

SUBJECT:	Ph.D. Proposal Presentation

BY:	Wenchao Zhou

TIME:	Thursday, January 26, 2012, 10:30 a.m.

PLACE:	MARC Building, 114

TITLE:	Droplet Impingement Dynamics and Polymerization for Inkjet deposition

COMMITTEE:	Dr. David W. Rosen, Chair (ME) Dr. Andrei G. Fedorov (ME) Dr. Levent Degertekin (ME) Dr. Martha A. Grover (ChBE) Dr. Wallace W. Carr (MSE)

SUMMARY Inkjet deposition enables more efficient, economic, scalable manufacturing for a wide variety of materials than other traditional additive techniques. The impact of droplets onto a substrate is critical for accuracy control and optimization of the droplet deposition process. A full understanding of droplets deposition process is critical to build an ink-jet printer to produce good quality parts with good accuracy control, to save manufacturing time and to reduce the complexity of the machine. This research is proposed to help understand the physics behind the polymeric droplet deposition process so that the deposition process can be well controlled to produce desired shape, which includes droplet impingement dynamics, polymerization kinetics and the coupling effects between them. There are many critical issues involved in this complicated droplet deposition process and this research shall seek to address some of the most research issues to help understand the droplet deposition process. The following research questions have been identified to be answered by this research: 1. How to characterize the droplet shape so that more information of the physics of the droplet impingement can be contained in this metric? 2. Which parameters have the most significant influence on the droplet shape evolution and how do these parameters affect the best achievable shape and the timing of it? 3. How to build a numerical model that can simulate the droplet impingement dynamics more efficiently than the conventional commercially available simulation software packages with adequate accuracy to enable 3-D simulation of the droplet impingement dynamics and make it possible to study the droplets interaction dynamics? 4. How to numerically model the coupling effects between the droplet impingement dynamics and polymerization dynamics to help understand this process? The intellectual merit of this research lies in developing scientific method and research tool by answering the above four critical research questions to help develop a strong scientific understanding of the physics behind droplets impingement dynamics and the polymerization kinetics and the coupling effects between them. This knowledge will help us decide the deposition parameters (including both impingement parameters and polymerization parameters) and control the deposition process to build the desired geometry.