1. 제 목 : Nanomaterial Based Flexible Electronics(굽혀지는 모니터와 태양전지)

2. 일 시 : 2009년 10월 16일 (금) 16:30-17:30

3. 연 사 : 고승환 교수(KAIST 기계공학과)

4. 장 소 : 301동 105호 강의실

5. 연사약력 :
- 2000 : (B.S.) Yonsei University, Mechanical Engineering
- 2000~2002 : (M.S.) Seoul Nat’l University, Mechanical and Aerospace Engineering
- 2002~2006 : (Ph.D.) UC Berkeley, Mechanical Engineering (advisor: Costas P. Grigoropoulos)
- 2007~ 2009 : Post doctoral fellow, Laser Thermal Lab, UC Berkeley
- 2007~ 2009 : CTO, nPrint Solutions, San Jose, CA
- Currently : Assistant professor, ANTS (applied nano technology and science) lab, Mechanical engineering, KAIST

6. 내용요약 :
Flexible electronics is the electrics built on flexible substrate, for example plastic, fabric, paper and metal foil. The beauty of this technology is the flexibility, lightweight and durability. And most of all, there is a big potential of substantial cost reduction through maskless processing or Roll-to-Roll processing. The flexibility means that the electronics do not need to be confined to a hard substrate or housing but provide the ability to conform, bend or roll into any shape. Essentially flexible substrates are lightweight and durable material compared with conventional rigid glass or silicon, therefore, they are perfect for portable electronics. Moreover, flexible substrates are cheap and can be made into any size and any length while large size glass or silicon substrates are very difficult and, if possible, very expensive to make. Cheap and large sized substrates allow a huge reduction in the material cost and a realization of the large area electronics that are impossible or too expensive with conventional rigid substrates. Usually flexible substrates have low melting temperature at the expense of flexibility. Most of the conventional metal deposition process is high temperature process and uses abundant corrosive chemicals. This makes the flexible substrate not compatible with those conventional IC processes. The development of direct printing of functional material has gained significant interest as an alternative to conventional integrated circuit (IC) process especially in the area of low cost, large area flexible electronics.
This talk will be composed of three major parts; (1) Material : nano-materials, (2) Processing : low temperature, non-vacuum, direct patterning processes, (3) Applications : flexible display & flexible solar cell.
(1) Materials : the unique properties and synthesis approaches needed for the flexible electronics fabrication will be discussed. Especially, how huge melting temperature drop (Tm,np <150°C) compared with bulk (Tm,bulk >1000°C) and very strong light (eg. laser) absorption contribute to the novel, low temperature fabrication method development for flexible electronics will be presented.
(2) Processing : recently developed novel, cost-effective, low temperature, environmentally friendly direct patterning methods will be discussed to get rid of conventional, expensive, vacuum & photo-lithographic fabrication processes. Several direct patterning methods developed by the speaker will be presented: (a) Selective laser sintering of inkjet printed metal nanoparticles and sprayed metal oxide nanoparticles, (b) Direct nanoimprinting of nanoparticle ink, (c) Nanomaterial enabled laser induced forward transfer (LIFT) of organic light emitting diode (OLED) material, (d) Direct synthesis and patterning of nanomaterials, (e) Laser aided micro/nano processing.
(3) Applications : how the above mentioned nanomaterial and novel direct patterning methods can be applied for device fabrication on a polymer substrate will be presented. The applications include (a) passive electrical components such as resistors and capacitors, (b) active components such as organic field effect transistor (OFET) and inorganic nanowires transistor, (c) organic light emitting diode (OLED), (d) dye sensitized solar cell (DSSC) on a polymer substrate.

7. 문 의 : 기계항공공학부 박종우 교수(☏ 880-7133)