(307a) Micro and Extended-Nano Fluidics Device Technology for Bioanalysis

Authors: 
Kitamori, T., The University of Tokyo



              Microfluidics and micro reactor technologies have been rapidly grown up, and extended their application range from basic science to industrial applications.  Our group also developed integrated chemical engineering in which pressure driven fluidic control was introduced and made its application expand to wide range of chemistry, chemical engineering and biomedical technologies.  Actually, some technologies were commercialized by our venture company Institute of Microchemical Technology IMT (http://www.i-mt.co.jp/e00top/eindex.html), and now many new comers from mainly bio, medical and environmental fields began to apply those micro chemical technologies to their own research with the products from IMT.  Commercialization and industrialization study has been moved from university to industry. 

              Now, our research curiosity turns to extended-nano (en) area in which fluidic channels and structures range from 10 to 100 nm orders.  Outstanding smallness is, of course, remarkable characteristic of the en fluidic channels.  However, the ultimate smallness brings out some unique properties of liquid and fluid in en spaces.  They are dominated by the surface and interface which surround en space.  We utilize both characteristic, ultimate smallness and unique properties, to novel analytical devices and energy devices, and also, we are elucidating the mechanism of such unique properties mechanism. 

              This lecture focuses on the utilization of ultimate smallness which is deeply relating to bioanalysis.  We fabricated en channels into glass microchips, and succeeded in fluidic control and chemical processing such as chromatographic separation and immunochemical reaction.  En channels are connected to micro channels, and these micro channels are substantial size interface between the en and our macro worlds.  Pico, femto, and atto litter analytical devices were successfully realized.  For example, atto litter chromatography was demonstrated, and two order of improvement on theoretical plates was proved.  Atto to pico litter is much smaller than the volume of a single cell, and therefore, single cell single molecule analysis with keeping the cell alive will be not a dream in the near future. 

              The unique properties of EN fluid are mainly brought by surface.  Viscosity, dielectric constant, proton mobility, conductivity, and other properties change in EN space.  The causes of them are revealing to be attributed to the behavior of proton which is provided by surface group.  These unique properties have been applied to novel energy devices.  Self hydrogen supplying fuel cell will be introduced as an example.  TiO2 nano structure was formed by bottom up fabrication in a microchannel, and Pt electrode was deposited on the bottom of another microchannel which was parallel to that.  These two parallel micro channels were connected by en channels.  When light was irradiated into the TiO2 nano structured channel, water inside the microchannel was decomposed and the generated proton passed through the en channels, because proton mobility in the en channels is 20 times larger than bulk water.  The escaped proton to the other microchannel combined and became as hydrogen gas.  Like this way, hydrogen gas fuel was successfully generated in the microchannel by light irradiation and separated by eb channels, and recovered as hydrogen gas.  This device utilize the characteristics of both micro and en spaces, and the novel function was obtained.  This fuel supplying device is promising to be a self rechargeable fuel cell in near future. 

              Some breakthrough technologies for micro and en fluidics, such as detection, surface modification, glass bonding, and fluid control methods will be also introduced.

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