PDMS valve-less micro pump structure and method for producing the same

Abstract

A PDMS valve-less micro pump structure includes a PDMS body having a contour surface, a membrane covering the contour surface of the PDMS body, and a PZT actuator located on the membrane. The contour surface of the PDMS body to be sealed by the membrane and the PZT actuator has in series a lead-in cavity, a lead-in nozzle structure, a main cavity, a lead-out nozzle structure, and a lead-out cavity. The PZT actuator is located right above the main cavity. By providing the PDMS as a material to form the body of the micro pump, the micro pump can then be mass-produced with less cost and simpler structuring. Also, substantial elasticity and bio-compatibility for the micro pump can be achieved.

1 . A PDMS valve-less micro pump structure, comprising: 
 a PDMS body, having a contour surface, the contour surface further being curved to form thereof: 
 a main cavity;  
 a lead-in cavity, located aside to the main cavity and in spatial communication with the main cavity through a lead-in nozzle; and  
 a lead-out cavity, located also aside to the main cavity and in spatial communication with the main cavity through a lead-out nozzle;  
   a membrane having a center hole, layered on top of the PDMS body by sealing the lead-in cavity, the lead-in nozzle, the lead-out nozzle and the lead-out cavity but having the center hole positioned on top of the main cavity; and    a PZT actuator, mounted on top of the membrane by a predetermined peripheral sealing way so as to seal the main cavity.    
   
   
       2 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said membrane is made of a PDMS material.  
   
   
       3 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said membrane has a thickness ranged between 200 μm and 300 μm.  
   
   
       4 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said predetermined peripheral sealing way is a sealing way having supports at nodes of said PZT actuator.  
   
   
       5 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said predetermined peripheral sealing way is a sealing way having supports at a periphery of said PZT actuator.  
   
   
       6 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said predetermined peripheral sealing way is a sealing way having bonding at a periphery of said PZT actuator.  
   
   
       7 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said PZT actuator has a bottom coated with a PDMS material.  
   
   
       8 . The PDMS valve-less micro pump structure according to  claim 1 , wherein said PZT actuator further comprising: 
 a PZT plate;    a copper plate, layered under the PZT plate;    an insulation layer, sandwiched between the PZT plate and the copper plate to avoid electrically shorting in between; and    a bottom layer, layered under the copper plate to prohibit direct contact between the copper plate and a fluid in said main cavity.    
   
   
       9 . The PDMS valve-less micro pump structure according to  claim 8 , wherein said insulation layer is made of a PDMS material.  
   
   
       10 . The PDMS valve-less micro pump structure according to  claim 8 , wherein said bottom layer is made of a PDMS material.  
   
   
       11 . A method for producing a PDMS valve-less micro pump structure, comprising the steps of: 
 preparing a die, the die having a profiling protrusion forming on a top surface thereof;    pouring a PDMS material in a fluid state onto the top surface of the die to cover fully the profiling protrusion;    performing a predetermined baking process on the die and the PDMS material to solidify the PDMS material; and    removing the solidified PDMS material from the die to complete a production of the PDMS valve-less micro pump structure;    wherein the profiling protrusion of the die is characterized to form concavely a main cavity, a lead-in cavity, a lead-in nozzle, a lead-out cavity and a lead-out nozzle in the PDMS material.    
   
   
       12 . The method for producing a PDMS valve-less micro pump according to  claim 11 , wherein said die is made of a PMMA material.  
   
   
       13 . The method for producing a PDMS valve-less micro pump according to  claim 11 , wherein said PDMA material in the fluid state is prepared by mixing a Sylgard 184 base and a Sylgard 184 agent at a 10:1 ratio.  
   
   
       14 . The method for producing a PDMS valve-less micro pump according to  claim 13 , wherein said Sylgard 184 base and said Sylgard 184 agent are blended by a magnetic stirrer by stirring a predetermined period at a predetermined speed and then slowing to de-bubble said PDMS material.  
   
   
       15 . The method for producing a PDMS valve-less micro pump according to  claim 11 , wherein said predetermined baking process is a vacuum-baking process including a 20-30 minute low-pressure de-bubbling step, a heating step at 110-130° C. for 2-4 hours, and a free cooling step.  
   
   
       16 . A method for producing a PDMS valve-less micro pump, comprising the steps of: 
 preparing a PDMS body, the PDMS body having a main cavity, a lead-in cavity, a lead-in nozzle, a lead-out cavity and a lead-out nozzle formed concavely on a contour surface thereof;    adhering a membrane having a center hole onto the contour surface of the PDMS body by sealing the lead-in cavity, the lead-in nozzle, the lead-out nozzle and the lead-out cavity but having the center hole positioned on top of the main cavity;    mounting a PZT actuator onto the membrane by a predetermined peripheral sealing way so as to seal the main cavity; and    performing a baking process to solidify the combination of the PDMS body, the membrane, and the PZT actuator.    
   
   
       17 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said membrane is made of a PDMS material.  
   
   
       18 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said membrane has a thickness ranged between 200 μm and 300 μm.  
   
   
       19 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said predetermined baking process is a vacuum-baking process including a heating step at 110-130° C. for 2-4 hours.  
   
   
       20 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said predetermined peripheral sealing way is a sealing way having supports at nodes of said PZT actuator.  
   
   
       21 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said predetermined peripheral sealing way is a sealing way having supports at a periphery of said PZT actuator.  
   
   
       22 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said predetermined peripheral sealing way is a sealing way having bonding at a periphery of said PZT actuator.  
   
   
       23 . The method for producing a PDMS valve-less micro pump according to  claim 16 , wherein said “mounting a PZT actuator onto the membrane by a predetermined peripheral sealing way” is performed by coating a PDMS solution to a bottom of said PZT actuator.