Microchip and particulate analyzing device

Abstract

A microchip is provided, which includes a substrate including a fluid channel structure. The fluid channel structure includes a first fluid introduction channel and a second fluid introduction channel configured to meet so as to allow merging of a first fluid introduced from the first fluid introduction channel and a second fluid introduced from the second fluid introduction channel. A tapered portion is configured to be positioned after merging the first fluid and the second fluid so as to suppress a spiral flow field generated after the merging.

1 . A microfluidic chip for use with a particulate analyzing device, the microfluidic chip comprising:
 a substrate; and   a fluid channel formed in the substrate, the fluid channel including:
 a supply port configured to receive a sample liquid flow; and 
 a merge channel configured to convert the sample liquid flow into a sheath liquid laminar flow, the merge channel having a first fluid converting structure, a second fluid converting structure, and a third fluid converting structure, to convert the sample liquid flow into the sheath liquid laminar flow by introducing sheath liquid into the fluid channel or changing a cross section area, wherein 
   the first, second, and third fluid converting structures are provided at different longitudinal locations along the fluid channel,   a first surface portion of the fluid channel lies in a first plane upstream of the second and third fluid converting structures,   a second surface portion of the fluid channel lies in a second plane vertically above the first plane downstream of the second and third fluid converting structures, and   the first fluid converting structure having a tapered portion narrowing the sample liquid flow in a first direction, the second fluid converting structure having a first portion narrowing the sample liquid flow in a second direction, and the third fluid converting structure having a second portion narrowing the sample liquid flow in the second direction, and the first direction is orthogonal to the second direction.   
     
     
         2 . The microfluidic chip of  claim 1 , further comprising a detection portion downstream of the first, second, and third fluid converting structures. 
     
     
         3 . The microfluidic chip of  claim 1 , wherein the first fluid converting structure is configured to introduce sheath liquid into the fluid channel symmetrically with respect to a centerline of the sample liquid flow. 
     
     
         4 . The microfluidic chip of  claim 1 , wherein the first fluid converting structure is configured to convert the sample liquid flow in at least a lateral direction. 
     
     
         5 . The microfluidic chip of  claim 1 , wherein the second fluid converting structure is configured to convert the sample liquid flow in at least a vertical direction. 
     
     
         6 . The microfluidic chip of  claim 1 , wherein the third fluid converting structure is configured to convert the sample liquid flow in at least a vertical direction. 
     
     
         7 . The microfluidic chip of  claim 1 , wherein the sample liquid flow and the sheath liquid associated with the first fluid converting structure enter the merge channel in a center line. 
     
     
         8 . The microfluidic chip of  claim 1 , wherein the merge channel has a varying width upstream of the second and third fluid converting structures; and
 wherein the fluid channel has a constant width between the second fluid converting structure and third fluid converting structure.   
     
     
         9 . The microfluidic chip of  claim 8 , wherein the fluid channel has a constant width between a detection portion and the second and third fluid converting structures. 
     
     
         10 . The microfluidic chip of  claim 1 , wherein within the merge channel the fluid channel transitions from a first cross section shape to a second cross section shape different from the first cross section shape. 
     
     
         11 . The microfluidic chip of  claim 1 , wherein
 a first surface of the fluid channel lies in a third plane upstream of the first and second fluid converting structures, and   a second surface of the fluid channel lies in a fourth plane vertically below the third plane downstream of the first and second fluid converting structures.   
     
     
         12 . The microfluidic chip of  claim 1 , wherein the first portion includes a tapered portion. 
     
     
         13 . The microfluidic chip of  claim 1 , wherein the second portion includes a contracted portion. 
     
     
         14 . The microfluidic chip of  claim 1 , wherein the merge channel includes a focusing region. 
     
     
         15 . A particulate analyzing device comprising:
 a detector configured to detect particulates in a sample liquid flow in a fluid channel formed in a substrate on a microfluidic chip, the fluid channel including:
 a supply port configured to receive the sample liquid flow; and 
 a merge channel configured to convert the sample liquid flow into a sheath liquid laminar flow, the merge channel having a first fluid converting structure, a second fluid converting structure, and a third fluid converting structure, to convert the sample liquid flow into the sheath liquid laminar flow by introducing sheath liquid into the fluid channel or changing a cross section area, wherein 
   the first, second, and third fluid converting structures are provided at different longitudinal locations along the fluid channel,   a first surface portion of the fluid channel lies in a first plane upstream of the second and third fluid converting structures,   a second surface portion of the fluid channel lies in a second plane vertically above the first plane downstream of the second and third fluid converting structures, and   the first fluid converting structure is a tapered portion narrowing the sample liquid flow in a first direction, the second fluid converting structure is a first portion narrowing the sample liquid flow in a second direction, and the third fluid converting structure is a second portion narrowing the sample liquid flow in the second direction, and the first direction is orthogonal to the second direction.   
     
     
         16 . The particulate analyzing device of  claim 15 , further comprising:
 a detection portion in the microfluidic chip downstream of the first, second, and third fluid converting structures.   
     
     
         17 . The particulate analyzing device of  claim 15 , wherein the first fluid converting structure is configured to introduce sheath liquid into the fluid channel symmetrically with respect to a centerline of the sample liquid flow. 
     
     
         18 . The particulate analyzing device of  claim 15 , wherein the first fluid converting structure is configured to convert the sample liquid flow in at least a lateral direction. 
     
     
         19 . The particulate analyzing device of  claim 15 , wherein the second fluid converting structure is configured to convert the sample liquid flow in at least a vertical direction. 
     
     
         20 . The particulate analyzing device of  claim 15 , wherein the third fluid converting structure is configured to convert the sample liquid flow in at least a vertical direction. 
     
     
         21 . The particulate analyzing device of  claim 15 , wherein the sample liquid flow and the sheath liquid associated with the first fluid converting structure enter the merge channel in a center line. 
     
     
         22 . The particulate analyzing device of  claim 15 , wherein the merge channel has a varying width upstream of the second and third fluid converting structures; and
 wherein the fluid channel has a constant width between the second fluid converting structure and third fluid converting structure.   
     
     
         23 . The particulate analyzing device of  claim 22 , wherein the fluid channel has a constant width between a detection portion and the second and third fluid converting structures. 
     
     
         24 . The particulate analyzing device of  claim 15 , wherein within the merge channel the fluid channel transitions from a first cross section shape to a second cross section shape different from the first cross section shape. 
     
     
         25 . The particulate analyzing device of  claim 15 , wherein
 a first surface of the fluid channel lies in a third plane upstream of the first and second fluid converting structures, and   a second surface of the fluid channel lies in a fourth plane vertically below the third plane downstream of the first and second fluid converting structures.   
     
     
         26 . The particulate analyzing device of  claim 15 , wherein
 the sample liquid flow is narrowed such that the particulates are arranged in a row downstream of the second and third fluid converting structures, and   the detector is configured to detect the particulates one by one.   
     
     
         27 . The particulate analyzing device of  claim 15 , wherein the detector is included in at least one of an optical detection system, an electrical detection system, or a magnetic detection system. 
     
     
         28 . The particulate analyzing device of  claim 15 , further comprising an optical detection system, which includes the detector, a laser beam source, an irradiation section including a condenser lens configured to condense the laser beam and irradiate the particulates, a dichroic mirror, and a bandpass filter. 
     
     
         29 . The particulate analyzing device of  claim 15 , wherein the detector comprises a pick-up element which is at least one of a photo multiplier tube, a CCD or a CMOS device. 
     
     
         30 . A system comprising:
 a particulate analyzing device; and   a microfluidic chip, wherein the microfluidic chip comprises:
 a substrate; and 
 a fluid channel formed in the substrate, the fluid channel including:
 a supply port configured to receive a sample liquid flow; and 
 a merge channel configured to convert the sample liquid flow into a sheath liquid laminar flow, the merge channel having a first fluid converting structure, a second fluid converting structure, and a third fluid converting structure, to convert the sample liquid flow into the sheath liquid laminar flow by introducing sheath liquid into the fluid channel or changing a cross section area, wherein 
 
   the first, second, and third fluid converting structures are provided at different longitudinal locations along the fluid channel,   a first surface portion of the fluid channel lies in a first plane upstream of the second and third fluid converting structures,   a second surface portion of the fluid channel lies in a second plane vertically above the first plane downstream of the second and third fluid converting structures, and   the first fluid converting structure having a tapered portion narrowing the sample liquid flow in a first direction, the second fluid converting structure having a first portion narrowing the sample liquid flow in a second direction, and the third fluid converting structure having a second portion narrowing the sample liquid flow in the second direction, and the first direction is orthogonal to the second direction.