Advanced Materials Processing and Manufacturing

 

 

 

 

Research

Current research topics:

1. Selective ultrasonic foaming of polymer for biomedical applications Funded by NSF

The objective of this research is to develop the science base, as well as the process optimization for the selective HIFU foaming process. A unique feature of the process is the two-level control of the hierarchical porous structures. On a large scale (sub-millimeters to millimeters), the porous structure is controlled through moving the focal spot of the HIFU transducer. On a smaller scale (micrometers), it is controlled by the gas foaming process. The new porous material is expected to find many emerging applications such as catalyst carriers for fuel cells, adsorption sites for bio-chemical sensors, and tissue engineering scaffolds. For more information, click here (PDF).

2. Multifunctional nanocomposite nanofoams Funded by NSF and Boeing

The goal of this project is to develop a processing method to fabricate ultra-light, multifunctional nanofoams from polymer nanocompoistes.  Such materials will have tailored electrical, thermal, and mechanical properties. They can be employed to perform multi-functions, such as load bearing, electro-static prevention, electro-magnetic shielding, acoustic damping, and maybe eventually even sensing. This research will focus on polymer composites with carbon nano tubes (CNT) and carbon nano fibers (CNF). We are studying the nucleation and foaming characteristics of these nanocomposites. The structure-property relationship of the foamed nanocomposite materials will also be studied.

3. Subcritical CO2 based microcellular extrusion Funded by NSF

This project is aimed at developing a sub-critical CO2 based microcellular extrusion process for environmentally benign plastics. The envisioned process will use low pressure CO2 as a blowing agent, providing a substitute for harmful chemical blowing agents and volatile gases now in use in manufacture of polymer foams. The research will focus on two environmentally benign plastics: recycled polyethylene terepthalate (PET) and naturally derived Polylactic Acid (PLA). The research focuses on modeling and control of the microcellular extrusion process.

4. Fabrication of 3D micro-scale tissue model system for drug discovery Funded by NIH

5. Solvent free fabrication of tissue engineering scaffolds

In this research, we develop a solvent-free fabrication approach for biodegradable porous polymer. Ultrasound is applied after the solid state foaming process to create interconnected porous structures in closed-cell foams. It has been found that biodegradable PLA can be foamed using the solid-state foaming process with a wide processing window and the inter-pore connectivity of the foams can be substantially enhanced by applying ultrasound treatment. The combined solid-state foaming and ultrasound processing method could provide a completely solvent-free approach to fabricating tissue engineering scaffolds. For more information, click here (PDF).

6. Passive porous polymeric micromixer

In microfluidic related chemical and biological applications, mixing on the micro scale is important and has been considered as one of the most challenging tasks. Specifically, rapid and efficient mixing of small quantities of reactants is essential in areas such as DNA hybridization, cell activation, and enzyme reaction. However, it is difficult to mix fluids in microfluidic systems due to the low Reynolds numbers involved, typically smaller than 10 (Re<10). Under such conditions, micromixing is mostly dominated by diffusion, which is time-consuming and inefficient. In this research, we develop a novel passive polymeric micromixer with 3D porous microstructure. The 3D porous microstructure dramatically improves the mixing efficiency of incoming flows. We have shown that the developed porous micromixer performed extremely well for Reynolds numbers as low as 0.1. For more information, click here (PDF).

 

Past projects:

  1. Washington Technology Center, Cordless Electronics Soldering Tool Based on Cold Heat Technology, PI, 8/01-5/02

  2. National Science Foundation, Microcellular Polymer Processing for Lightweight and Energy Efficient Advanced Panel Systems, Co-PI, 9/01-8/03

  3. Washington Technology Center, A Novel Cooling Strategy for Improving Productivity of the Recycled Plastic Lumber Production Process, Co-PI, 7/01-6/02

  4. National Science Foundation, NER: Creation of Polymeric Nanofoams using Retrograde Vitrification, Co-PI, 7/02-6/03

  5. Hyperion Innovation, Inc., Modeling the Thermal Electrical Process of the Hyperion Soldering Tool, PI, 12/01

  6. RRF of University of Washington, Resistance Heat Assisted Self Piercing Riveting for New Generation Auto Body Assembly, PI, 7/02-6/03

  7. Hyperion Innovation, Inc., Resistance Soldering Tool, PI, 2/03

  8. Washington Technology Center, A New Process Control Strategy for Productivity Enhancement and Variation Reduction of Recycled Plastic Lumber Production, Co-PI, 7/02-6/03

  9. Washington Technology Center, Feasibility Study on Gas-Impregnated Thermoforming of Microcellular PET Foams, Co-PI, 4/03-9/03

  10. Genie Industries, Mast Welding Process Simulation, PI, 6/03-2/04

  11. National Science Foundation, Feasibility Study on Fabrication of Open-cell Biodegradable Polymer Foams using Ultrasonic Implosion for Tissue Engineering Scaffolds, PI, 5/03-12/04

  12. Genie Industries, Integrated Product and Process Design through Simulation of Mast Welding, PI, 4/1/04-6/15/06

  13. DaimlerChrylser Corporation, Equipment Donation: A 150KVA Plant Scale Spot Welder, PI, 2/02

  14. DaimlerChrysler Corporation, Spot Weld Monitoring and Control, PI, 8/1/03-7/30/05

  15. The Boeing Company, Feasibility of Determining the Deformed Shape of a Flexible Part during Its Measurement Process using Finite Element Analysis, PI, 11/1/05-9/30/06