Micro total analysis system equipped with leakage prevention mechanism

Abstract

A micro total analysis system, comprising: an examination chip provided with a micro flow path and a flow path opening section communicating with a micropump on the upstream side of a reagent containing section, a drive fluid tank containing drive fluid, a micropump unit provided with a plurality of the micropumps such that the upstream side of each micropump communicates with the drive fluid tank and a flow path opening communicating with the micro flow path of the examination chip is provided on the downstream side, and a system body including the micropump unit and the drive fluid tank in one storing body, wherein analysis is performed while the examination chip is attached to the system body, and a mechanism for altering the direction of pressure at the flow path opening of the micropump unit depending on attaching/detaching of the examination chip to/from the system main body is provided.

1 . A micro total analysis system, comprising:
 an examination chip provided with a succession of a micro flow path and a flow path opening section at an upstream side of a containing position of a reagent in the micro flow path, wherein the flow path opening section is communicated with a micropump;   a drive fluid tank to contain a drive fluid which pushes the reagent the upstream side to a downstream side of the micro flow path of the examination chip;   a micropump unit provided with a plurality of the micropumps on a surface of a chip, wherein an upstream side of each micropump is communicated with the drive fluid tank and a downstream side thereof is communicated with the micro flow path of the examination chip at the flow path opening section;   a system main body wherein the micropump unit and the drive fluid tank are integrated and stored in a storing body; and   a mechanism to change a direction of liquid feeding pressure at the flow path opening section of the micropump unit in response to detaching and attaching of the examination chip while carrying out analysis of the analyte in a state where the examination chip is attached to the system device main body;   wherein the examination chip is connected to the micropump unit in a way that the flow path opening sections are overlapped, the micropump feeds the drive fluid to the micro flow path of the examination chip to push out the reagent to the downstream side so that the reagent and the analyte are merged and reacted, and the reaction is detected, whereby a target substance in the analyte is analyzed.   
   
   
       2 . The micro total analysis system of  claim 1 , wherein all the micropumps in the micropump unit are connected to a single drive fluid tank so that the drive fluid stored in the drive fluid tank is fed through each micropump to the micro flow path of the examination chip. 
   
   
       3 . The micro total analysis system of  claim 1 , wherein a pressure opposite to an ejection direction of the micropump is applied at the flow path opening section of the micropump unit being connected to the examination chip at least when the examination chip is detached from the flow path opening section of the micropump unit. 
   
   
       4 . The micro total analysis system of  claim 1 , wherein the pressure opposite to the ejection direction of the micropump is applied as a negative pressure at the flow path opening section of the micropump unit being connected to the examination chip only when the examination chip is detached from the flow path opening section of the micropump unit. 
   
   
       5 . The micro total analysis system of  claim 4 , wherein the negative pressure is created by lowering a fluid surface of the drive fluid tank than a connection section to the examination chip. 
   
   
       6 . The micro total analysis system of  claim 1 , wherein the drive fluid tank can be move up and down. 
   
   
       7 . The micro total analysis system of  claim 1 , wherein the pressure of the drive fluid at the flow path opening section of the micropump unit is changed through a negative pressure generation mechanism attached to a cartridge type drive fluid tank. 
   
   
       8 . The micro total analysis system of  claim 7 , wherein the negative pressure generation mechanism creates the pressure opposite to the ejection direction of the micropump through a bias force created by a restitution force of an elastic substance. 
   
   
       9 . The micro total analysis system of  claim 4 , wherein an absolute value of the negative pressure is 5 mmAq at a maximum. 
   
   
       10 . The micro total analysis system of  claim 1 , wherein the micropump comprises;
 a first flow path, wherein a flow path resistance varies with a pressure difference,   a second flow path, wherein a change rate of the flow path resistance in respect to a change of the pressure difference is smaller than that of the first flow path,   a pressure chamber connected to the first flow path and the second flow path, and   an actuator driven by voltage so as to change an inner pressure of the pressure chamber.