Integrated Nanostructured Systems

Recently, the SMALL has demonstrated that serial dilution-based microfluidic circuits can generate not only a linear gradient (a) but also a 10-fold logarithmic gradient (b). The proposed gradient generation technology enables to create concentration gradients (e.g., conductivity, permittivity, pH, fluorescence, chemical and biomolecular concentration) with a shape of any desired monotonic functions (e.g., linear, logarithmic, polynomial, sine, exponential, Gaussian) as well as arbitrary output flow rate gradients. Successful accomplishment of the universal gradient generator will address many challenges of gradient-dependent phenomena in science and engineering.

BioMEMS; Lab-on-a-Chip (LOC); Micro Total Analysis Systems (uTAS); Micro/nanofluidics; nanobiosensors; microactuators.

Currently, the SMALL is developing droplet-based microfluidic systems, universal microfluidic concentration generators, continuous-flow cell separators, energy harvesting micro/nanofluidic devices, and so on. Dr. Oh has actively been engaged in BioMEMS, microfluidics and their LOC applications in academic and industrial settings. In the past, he developed microfluidic devices and systems for magnetic bead-based biochemical detection, magnetically driven microvalves and micropumps, real-time micro PCR (polymerase chain reactions) devices and system for Hepatitis B virus (HBV) detection, and world-to-chip microfluidic interfacing for micro PCR and LOC devices.

The SMALL (nanobioSensors and MicroActuators Learning Lab) is located in Bonner Hall (rooms 207A, 323, 326), which houses Electrical Engineering department in the UB north campus. The SMALL consists of a suite of PDMS rapid prototyping facilities, measurement and control equipments, automated control set-ups for microfluidics experiment, electroplating baths (for Ni, Cu, permalloys and ferromagnetic materials), and office spaces. The SMALL also is equipped with a state of the art Olympus MVX-10 high-performance fluorescence imaging stereoscope with Hamamatsu ORCA ERGA monochrome digital camera & Hamamatsu software. Recently, a brand-new BOC Edward Auto 500 e-beam deposition system, which is a unique system that can do sequential evaporation of up to 4 materials without braking vacuum, was placed in the EE department cleanroom.

The SMALL is accessible to simulate using several softwares: CFD-ACE, ANSYS, COMSOLE, and AUTO-CAD.

Kwang W. Oh and Chong H. Ahn, "Magnetic Actuation," Comprehensive Microsystems, 2, 39-68, 2008, Elsevier, Oxford, UK.

Kwang W. Oh and Chong H. Ahn, "A review of microvalve," Journal of Micromechanics and Microengineering, 16, R13-R39, 2006 (Selected for inclusion in the IOP Physics Reviews, March 2006; selected at JMM Top-25 Highlights of 2006).

Y.-K. Cho, J. Kim, Y. Lee, Y.-A. Kim, K. Namkoong, H. Lim, Kwang W. Oh, S. Kim, J. Han, C. Park, Y. E. Pak, C. Ko, C.-S. Ki, J. R. Choi, and H.-K. Myeong, "Clinical evaluation of micro-scale chip-based PCR system for rapid detection of HBV," Biosensors and Bioelectronics, 21, 2161-2169, 2006 (Selected as ScienceDirect TOP-25 hottest articles).

D. S. Yoon, Y.-K. Cho, Kwang W. Oh, S. H. Kim, Y. A. Kim, J. I. Han, and G. Lim, "A microfluidic gel valve device using reversible sol-gel transition of methyl cellulose for biomedical application," Microsystem Technologies, 12, 238-246, 2006.

Kwang W. Oh, C. Park, K. Namkoong, J. Kim, K.-S. Ock, S. Kim, Y.-A. Kim, Y.-K. Cho, and C. Ko, "World-to-chip microfluidic interface with built-in valves for multichamber chip-based PCR assays, " Lab Chip, 5, 845-850, 2005 (Selected for inclusion in the RSC’s Chemical Biology Virtual Journal, Issue 12, 2005).

Kwang W. Oh, R. Rong, and C. H. Ahn, "Miniaturization of pinch-type valves and pumps for practical micro total analysis system integration," Journal of Micromechanics and Microengineering, 15, 2449-2455, 2005.

J.-W. Choi, Kwang W. Oh, J. H. Thomas, W. R. Heineman, H. B. Halsall, J. H. Nevin, A. J. Helmicki, H. T. Henderson, and C. H. Ahn, "An integrated microfluidic biochemical detection system for protein analysis with magnetic bead-based sampling capabilities," Lab Chip, 2, 27-30, 2002.

D. S. Yoon, Y.-S. Lee, Y. Lee, H. J. Cho, S. W. Sung, Kwang W. Oh, J. Cha, and G. Lim, "Precise temperature control and rapid thermal cycling in micromachined DNA polymerase chain reaction chips," Journal of Micromechanics Microengineering, 12, 813-823, 2002.