Vertical liquid transportation through capillary bundle structure using centrifugal force

Abstract

The use of three-dimensional (3D) microstructures is becoming essential attempt to develop next generations' microdevices, to integrate many modules and various functions, and enhance the performance of device. In this paper, we present a new concept for lab on a chip using 3D structure and centrifugal pumping for integrated functional fluid systems such as high-throughput screening, and point of care testing systems which has stacked multiple structures with 3D-interconnection. The use of 3D structure brings many benefits for above high throughput systems, such as possibility to integrate various modules enabling to perform total assay operation, from sample preparation for biochemical reaction and their detection on one platform. For this concept, the most important key technology is control of a vertical valving and transportation of liquid between different 2D micro channel networks with different height levels. We demonstrated such vertical liquid transportation in 3D micro channel networks through the high aspect ratio capillary bundle filter by controlling spinning speed of device and centrifugal force as a pumping force, and confirmed capillary bundle could be employed as vertical microvalve for 3D fluidic systems using centrifugal force as a pumping method.

Development and characterization of ultra high aspect ratio microstructures made by ultra deep X-ray lithography

“…Since that time a continuous increase in the aspect ratio has been observed. This trend is based on the requirements of numerous manufacturing applications, for example X-ray gratings (Reznikova et al, 2008), gas chromatography columns (Bhushan et al, 2007), micro-capillary filters (Kondo et al, 2010), magnetic coils (Turner et al, 1996), X-ray telescopes (Ezoe et al, 2010), micro-gears (Meyer et al, 2008), micro-capacitors with high AR cantilever (Haluzan et al, 2008), etc. To this end, the sidewalls in the technological layer of so called resist should be close to vertical.…”