intelligent †MICROSYSTEM† LABORATORY (i M L)
I. On-chip self-calibration/self-diagnosis of biochemical microsensors
Unpredictable baseline drift and sensitivity degradation during continuous use are the most significant problems of biosensors. The capability of on-chip, on-demand, in situ self-calibration/self-diagnosis of biosensor microchips is therefore inevitable for continuous monitoring with minimum human intervention. With the integrated microelectrodes in the microsensor chips, two kinds of microenvironment, called the oxygen-saturated or oxygen-depleted phases, can be created by water electrolysis. The accuracy and viability of dissolved gas sensors (dissolved oxygen) sensors and oxidase enzyme-based biosensors (glucose and lactate) can be checked periodically in this microenvironment based on the oxygen dependency of sensor signals. Various types of devices are being designed and characterized to explore this novel on-chip intelligent functionality.
[Novel microsensors (dissolved oxygen sensors and oxidase enzyme biosensors) with integrated on-chip, in situ self-calibration/self-diagnosis modules by actively creating the calibration microenvironment around the microsensors.]
II. Microsensor array for plant root zone monitoring in a space environment
Plant growth experiments in space require new nutrient delivery concepts in which water and nutrients are replenished on a continuous basis for long-term healthy growth of plants. The goal of this study is to develop a novel microsensor array to provide the adequate environment to the plant root zone for optimum control of plant cultivation systems in the space environment. The microsensor array is fabricated on a flexible polymer substrate. Measurements either in a porous tube plant cultivation system or in a particulate substrate growth media are made. The unique features of the sensors (small size, multiple sensors, and mechanical flexibility) have benefits for the study and optimization of plant cultivation systems in both terrestrial and microgravity environments.
[Simplified diagram of the porous tube nutrient delivery system (PTNDS) for the plant growth in microgravity environment and a close view of the flexible microsensor array (Kapton‚ substrate) wrapping the porous tube to monitor the root zone environment.]
III. Process development of photopolymer (SU-8) bio-MEMS devices
There have been growing interests in using polymers in bio-MEMS devices due to its high flexibility in designing complicated microstructures. The organic-based, high-aspect ratio, photo-responsive polymers, such as epoxy-based SU-8 photoresist, are the promising candidates. We are developing novel methods to utilize the SU-8 material for bioanalytical devices applications. A hydrogel photografting method is being investigated to modify the SU-8 surface in order to manipulate the wettability and to attach functional layers. Reactive ions etch methods are also being developed to selectively remove the fully cured bulk SU-8 material after the use as electroplating molds or temporary structures.
[Left: Photoinitiators are irradiated and react with the SU-8 surface, and then monomers are added to grow off covalently grafted polymers. Right: Photograph of a microfludic channel selectively etched by CF4-O2 plasma.]
IV. Integrated microfluidic substrate for rhizosphere study
The objective of this work is to develop a vertical array of electrochemical/optical microsensors combined with a fluidic network to study the rhizosphere environment (the plant root and the immediate root zone interaction).
PAST AND CURRENT SPONSORS
1. Raghu Amberkar, David B. Henthorn, Chang-Soo Kim, Photopatternable optical membranes for integrated optical sensors for chemical detection, IEEE Sensors Journal, Accepted, 2008.
2. Zhefei Li, Frank Blum, Massimo Bertino, Chang-Soo Kim, One-step fabrication and characterization of polyaniline nanofibers sensor, Sensors & Actuators B-Chemical (Elsevier), Accepted, 2008.
3. Zhan Gao, David B. Henthorn, Chang-Soo Kim, Enhanced wettability of SU-8 photoresist through a photografting procedure for bioanalytical device applications, Journal of Micromechanics and Microengineering (IoP), 18(4), article no. 045013, 2008.
Sathyan, Chang-Soo Kim,
6. Jongwon Park, Chang-Soo Kim, Youngjin Kim, A simple on-chip self-diagnosis/self-calibration method of oxygen microsensor using electrochemically generated bubbles, Sensors & Actuators B, Chemical (Elsevier), 108, 633-638, 2005.
Kim, Chae-Hyang Lee, Jason O. Fiering, Stefan Ufer, Charles W. Scarantino,
Kim, Stefan Ufer, Christopher M. Seagle, Connie L. Engle,
1. Nitin Radhakrishnan, Jongwon Park, Chang-Soo Kim, Microfluidic creatinine biosensors with high sensitivity and low electrochemical interferences, Paper ID 1180-13P (accepted), Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (PITTCON 2008), New Orleans, LA, Mar 2-7, 2008.
2. Phaninder Kanikella, Matthew OíKeefe, Chang-Soo Kim, Process development and application of dry film photoresist in MEMS, Paper ID 6882-20, SPIE Photonics West, San Jose, CA, Jan 19-24, 2008.
3. Raghu Ambekar, Zhan Gao, David B. Henthorn, Jongwon Park, Chang-Soo Kim, Process development for waveguide chemical sensors with integrated polymeric sensitive layers, Paper ID 6886-32, SPIE Photonics West, San Jose, CA, Jan 19-24, 2008.
Z. Gao, C.-S.
Kim, and D. B. Henthorn, "Post-bonding modification of microfluidic
channel materials for the manufacture of bioanalytical devices", 2007 AIChE Annual Meeting,
6. Zhan Gao, David B. Henthorn, Chang-Soo Kim, Zhan Gao, David B. Henthorn, Chang-Soo Kim, New enzyme immobilization method on microfluidic channel surfaces for bioanalytical applications, The 12th Annual Meeting of Institute of Biological Engineering, St. Louis, MO, Mar 29-Apr 1, 2007.
7. Jongwon Park, Phaninder Kanikella, Nitin Radhakrishnan, Chang-Soo Kim, A microsystem for zero-value calibration towards continuous glucose monitoring, 6th Annual Diabetes Technology Meeting, A133, Atlanta, GA, Nov 2-4, 2006.
8. Martin G. Perez, Phaninder Kanikella, James Reck, Chang-Soo Kim, Matthew J. OíKeefe, Process development for the formation of post-bonding biorecognition layers in microfluidic biosensors, IEEE Sensors Conference, Paper ID B2P-H1 (CD-ROM), Daegu, South Korea, Oct 22-25, 2006.
9. Zhan Gao, David B. Henthorn, Chang-Soo Kim, Surface modification of SU-8 by photografting of functional polymers for lab-on-a-chip applications, IEEE Sensors Conference, Paper ID A2P-G3 (CD-ROM), Daegu, South Korea, Oct 22-25, 2006.
10. David B. Henthorn, Zhan Gao, Chang-Soo Kim, Photopatterned surface modification of SU-8 photoresist for lab-on-a-chip applications, Paper ID 496C, 2006 AIChE Annual Meeting, San Francisco, CA, Nov 12-17, 2006.
Yellambalase, Jongwon Park, Chang-Soo Kim, Minsu Choi, Nohpill
Park and Fabrizio Lombardi, Automated
Oxidase-Coupled Amperometric Microsensor with Integrated Electrochemical
Actuation System for Continuous Sensing of Saccharoids,
IEEE Instrumentation and Measurement Technology Conference (IMTC 2006), pp.
12. Chang-Soo Kim, Sandeep Sathyan, D. Marshall Porterfield, New microsensor system for plant root zone monitoring, Paper ID P19, IEEE Sensors Conference, Irvine, CA, Oct 31-Nov 3, 2005.
13. Chang-Soo Kim, D. Marshall Porterfield, Microsystems to study interactions between plant roots and the root zone, Paper ID T135E, 9th International Conference on Miniaturized Systems for Chemistry and Life Sciences, Boston, MA, Oct 9-13, 2005.
14. Chang-Soo Kim, Jongwon Park, A novel biofluidic glucose electrode towards continuous extracorporeal glucose monitoring, p. A70, 5th Annual Diabetes Technology Meeting, San Francisco, CA, Nov 10-12, 2005.
Kim, An intelligent fluidic biosensor system utilizing electrolytic gas
bubbles for in situ self-calibration, Environmental Sentinels,
16. Chang-Soo Kim, Jongwon Park, Influences of oxygen microenvironments on a microfluidic glucose sensor performance, 3rd International IEEE-EMBS Special Topic Conference on Microtechnologies in Medicine & Biology, Ohau, Hawaii, May 12-15, 2005.
19. Jongwon Park, Chang-Soo Kim, Intelligent glucose microsensor with an integrated actuation system, 2004 Biomedical Engineering Society Annual Fall Meeting (BMES 2004), Paper ID 665, Philadelphia, PA, Oct 13-16, 2004.
21. Chang-Soo Kim, Functional/structural integration of microbiosensor using "electrochemical actuation" (quad-chart in CD-ROM), NSF Workshop on Control & System Integration of Micro- & Nano-scale Systems Washington DC, Mar 29-30, 2004.
Last update: 08/10/08