Linear peristaltic pump

Abstract

An improved technique for delivering a fluid to an outlet from a storage container takes the form of a linear peristaltic pump which enables the use of two elements: a single bearing and a valve. The single bearing provides enough pressure to a flexible tube in which the fluid moves to close the tube off at a single location. The valve controls the fluid flow out of the flexible tube at the egress point in conjunction with the bearing and is attached to the flexible tube at a single location. In this manner, when the bearing is engaged with the flexible tube, the bearing divides the flexible tube into two subvolumes, one of which contains fluid to be moved toward the egress point at the far end of the flexible tube and the other creating suction for intake of fluid immediately behind the bearing. A bearing controller moves the bearing along the surface of the flexible tube when so engaged; in doing so, the bearing moves the fluid.

1 . A peristaltic pump device configured to move a fluid from a storage container along an interior of a flexible tube, the peristaltic pump device comprising:
 a single roller constructed and arranged to apply pressure to an outer surface of the flexible tube when fluid from the storage container is in the interior of the flexible tube;   a roller controller constructed and arranged to constrain the single roller to movements (i) along the outer surface of the flexible tube, (ii) toward the outer surface of the flexible tube to provide a compression of a volume of the interior of the flexible tube, the compression sufficient to divide the volume of the interior of the flexible tube into two distinct subvolumes and (iii) away from the outer surface of the flexible tube to relieve the compression; and   a valve attached to the flexible tube at a single location, the valve constructed and arranged to, in conjunction with the single roller, control flow of the fluid through the interior of the flexible tube.   
     
     
         2 . A peristaltic pump device as in  claim 1 , wherein the flexible tube has a near end and a far end, the near end of the flexible tube attached to the storage container; 
       wherein the valve is located in the vicinity of the far end of the flexible tube; and
 wherein the motion of the roller controller along the outer surface of the flexible tube is constructed and arranged to, in conjunction with the valve, deliver a predetermined volume of the fluid to a fluid delivery device at a predetermined rate. 
 
     
     
         3 . A peristaltic pump device as in  claim 1 , wherein the flexible tube has a near end and a far end, the near end of the flexible tube attached to the storage container;
 wherein the valve is located in the vicinity of the near end of the flexible tube; and   wherein the motion of the roller controller along the outer surface of the flexible tube is constructed and arranged to, in conjunction with the valve, take in a predetermined volume of the fluid to the interior of the flexible tube.   
     
     
         4 . A peristaltic pump device as in  claim 2 , wherein the fluid is a photoresist; and
 wherein the far end of the flexible tube connects to a spin-coat device through which the photoresist is delivered to a substrate as a substantially flat layer on the substrate.   
     
     
         5 . A peristaltic pump device as in  claim 2 , wherein the roller controller includes:
 a servo motor which includes an output shaft, the servo motor being constructed and arranged to move the output shaft at a substantially constant angular velocity; and   a linkage system which connects the movement of the output shaft to that of the single roller.   
     
     
         6 . A peristaltic pump device as in  claim 2 , further comprising:
 a bubble catcher attached to the far end of the flexible tube, the bubble filter being constructed and arranged to remove air bubbles from the fluid.   
     
     
         7 . A peristaltic pump device as in  claim 2 , wherein the valve has a near end and a far end, the far end pointing away from the flexible tube; and
 wherein the valve provides suckback capability on its far end.   
     
     
         8 . A method of moving a fluid from a storage container along an interior of a flexible tube, the method comprising:
 drawing the fluid from the storage container to a near end of the flexible tube;   moving a single roller to an outer surface of the flexible tube, the moving ceasing when the single roller divides the interior of the flexible tube into two distinct subvolumes;   moving the single roller along the outer surface of the flexible tube while maintaining a pressure sufficient for the interior of the flexible tube to remain divided into the two subvolumes; and   operating a valve constructed and arranged to control flow of the fluid through the interior of the flexible tube to a far end of the flexible tube, the valve attached to the flexible tube at a single location.   
     
     
         9 . A method as in  claim 8 , wherein the valve is located in the vicinity of the far end of the flexible tube; and
 wherein moving the single roller along the outer surface of the flexible tube comprises:
 delivering, in conjunction with the valve, a predetermined volume of the fluid to a fluid delivery device at a predetermined rate. 
   
     
     
         10 . A method as in  claim 8 , wherein the valve is located in the vicinity of the near end of the flexible tube; and
 wherein moving the single roller along the outer surface of the flexible tube comprises:
 delivering, in conjunction with the valve, a predetermined volume of the fluid to the interior of the flexible tube. 
   
     
     
         11 . A method as in  claim 9 , wherein the fluid is a photoresist; and
 wherein moving the single roller along the outer surface of the flexible tube further comprises:
 delivering, through a spin-coat device connected to the far end of the flexible tube, the photoresist to a substrate as a substantially flat layer on the substrate. 
   
     
     
         12 . A method as in  claim 9 , wherein moving the single roller along the outer surface of the flexible tube further comprises:
 moving an output shaft of a servo motor at a substantially constant angular velocity, the output shaft being connected to a linkage system which connects the movement of the output shaft to that of the single roller.   
     
     
         13 . A method as in  claim 9 , further comprising:
 removing air bubbles from the fluid.   
     
     
         14 . A method as in  claim 9 , wherein the valve has a near end and a far end, the far end pointing away from the flexible tube; and
 wherein the method further comprises:
 providing suckback capability at the far end of the valve.