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MAE PhD Defense – Joong Hee Min
March 20, 2017 @ 9:30 am - 12:30 pm
Title: Design and Characterization of Thin Metallic Nanostructures for Flexible Transparent Conductors (Advisor: Dr. Chih-Hao Chang)
Date: March 20, 2017
Time & Location: 9:30 AM-12:30 PM EB3 – 3235
There have been numerous interests on developing both flexible and transparent conductors using various fabrication technologies, such as dispersing nanomaterials onto elastomeric substrates, or using pre-strained thin materials which can be stretched and compressed. Another effective technique is atomic layer deposition (ALD), one of the most powerful techniques to create those ultra-thin layers of new materials. Since metal nanostructures can be an attractive solution due to their excellent structural stability as well as superb electrical and thermal conductivity, the metal ALD combining with lithographic techniques will be a promising approach for fabricating flexible transparent conductors.
Here I develop a novel method to fabricate three-dimensional (3D) metallic nanostructures using platinum or tungsten ALD on lithographically patterned polymer templates. These free-standing nanostructures resemble accordions that are mechanically stretchable, and can be controlled by designing the template geometry. Then, using a simple pattern transfer process onto soft substrate, I characterize the fabricated flexible transparent metallic conductors and demonstrate the advantages from their mechanical, electrical, and optical properties. These metallic nano-accordion structures exhibit excellent electrical properties with high stretchability and I expect to find applications not only in flexible/stretchable electronic, but also in photonic devices and nanofluidics.
Joong Hee Min is a Ph.D candidate in Department of Mechanical and Aerospace Engineering at North Carolina State University, under the supervision of Dr. Chih-Hao Chang. He received B.S. and M.S. degree in mechanical engineering from Yonsei University, Seoul, South Korea in 2006 and 2008, respectively. Then, he came to U.S. and earned another M.S. degree in biological engineering from Purdue University, West Lafayette, Indiana in 2012. His research interests include design, fabrication, and characterization of nanostructured materials, and their applications, such as flexible, stretchable electronics.