1. SEMINAR
1. Title : Solution-based Thin-film Formation of Carbon and Organic Materials for Field-Effect Transistors and Sensors
2. Speaker : Steve Park (KAIST, Materials Science and Engineering)
3. Time : 16:00 – 17:00, Thursday, December 1st, 2016
4. Place : e+ Lecture Hall (room 83188), 2nd Research Building, Sungkyunkwan University
5. Summary :The field of electronics is entering into a new era with new and exciting applications such as wearable electronics, flexible electronics and optoelectronics, and implantable bioelectronics. Being competitive in these markets will require manufacturing of devices with competitive cost and performance. In this talk, I will discuss solution-based thin-film formation of single-walled carbon nanotubes (SWNTs) and organic materials to fabricate low-cost electronics and sensors with enhanced performance. To process thin-film of SWNTs as channel material in transistors, two main challenges exist—elimination of metallic SWNTs and dense alignment of SWNTs. To address the former, I have developed a polymer-based sorting technique that was shown to selectively disperse semiconducting SWNTs with a narrow diameter range of nm. The address the latter, I have developed solution shearing technique to densely align SWNTs over a large area in a facile manner with density as high as 200 tubes/micron. Also using SWNTs, stretchable capacitive tactile sensor were fabricated with high sensitivity of 0.7 kPa-1 and with the ability to differentiate between different tactile inputs. To print thin films of small organic molecules, a technique known as CONNECT was developed where organic crystals were aligned, self-patterned, and self-registered within the transistor channel over a large area. Transistor density as high as 840 dpi with low relative variance of 26% were demonstrated, along with a 2-bit half adder circuit. Finally, using ferroelectric polymer, PVDF, implantable microphone was fabricated, which was inserted into the cochlea to measure intracochlear sound pressure. In summary, the performance of SWNTs and organic thin films have been enhanced through novel solution processing techniques, through which transistors and various sensors were fabricated.
6 Background : Dr. Steve Park is currently an assistant professor in the materials science and engineering department at KAIST. He received his dual Bachelor’s degree in materials science and engineering and physics with magna cum laude from the University of Illinois at Urbana-Champaign and Knox College in He then worked as a technical staff for NanoInk Inc., developing commercial applications of dip-pen nanolithography until Dr. Park then received his Master of Science and Ph D from Stanford University in Materials Science and Engineering under the Prof. Zhenan Bao in 2014, researching on carbon nanotube and organic-based electronics. He then conducted his postdoctoral work at Columbia University in the electrical engineering and biomedical engineering department, working on piezoelectric polymer-based cochlear implants. Dr. Park is authored in over 19 peer-reviewed publications, holds 3 patents (2 additional patent applications pending), has been invited to multiple conferences, and is a member of Phi Beta Kappa academic honor society.
7. Questions : (☏ )