Nanofabrication for Bio-Information Technology
Speaker: Prof. Ki-Bum Kim, Seoul National University
Series: Topical Seminars
Location: Engineering Quadrangle B205
Date/Time: Thursday, February 24, 2011, 2:00 p.m. - 3:00 p.m.
The fabrication of nanometer scale features such as quantum dots and quantum wires in a controllable and economically viable manner is one of the essential requirements for the production of future ultra-high-density electronics, photonics, magnetic, and biological sensors and devices. In this talk, I will discuss a new method of patterning nanometer-scale periodic structures with much improved throughput by employing the various crystalline lattice images available in high resolution transmission electron microscopy (HRTEM) which is named as AIPEL (Atomic Image Projection Electron-beam Lithography).
Then, I will change the subject to the nanopore fabrication by utilizing the same transmission electron microscope. The demonstration of single molecule sequencing with biological nanopores, most notably ï?¡-hemolysin protein that spontaneously embedded themselves in a lipid bilayer, greatly accelerates the work to mimic this structure in solid-state. Accordingly, various methodswere proposed to form sub-10 nm, preferably down to 2 nm scale nanopore on the membrane structure utilizing either ion beam or electron beam perforation. These structures were interposed between cis- and trans-liquid chambers and successfully utilized to monitor the flow of DNA molecules by measuring the ionic current between cis- and trans-chambers.
While these works presented interesting results, namely, demonstrating the transport of single stranded DNA through the nanopore when an electrical bias is applied, the scientific information one could harvest from these experiments is quite limited. Most importantly, the translocation time is too fast to obtain the information on the types of bases. In order to analyze the base types (namely, A, T, G, C), which is separated only 0.34 nm, it is important to design a structure where the translocation of DNA through the pore is well controlled. Recently, our group, in collaboration with the members of IBM, reported the formation of multiple nanopore structure by utilizing electron beam lithography and atomic layer deposition (ALD) with the pore size less than 10 nm. More importantly, this structure has built-in gate electrode, just like MOS transistors for semiconductor device, and can control the transport of ions. It is expected that this device can also be utilized to control the transport of DNA and other bio-molecules.