Pipette-fillable cartridge fluid detection

Abstract

A digital dispense system and method of using a digital dispense system. The digital dispense system includes a pipette-fillable fluid cartridge having one or more fluid chambers therein and having an ejection head attached thereto. The ejection head contains a plurality of fluid ejectors thereon. The fluid ejectors are in fluid flow communication with the one or more fluid chambers of the pipette-fillable fluid cartridge. A fluid detection circuit is disposed on the ejection head and associated with at least one of the plurality of fluid ejectors for signaling the presence or absence of fluid in the one or more fluid chambers.

What is claimed is: 
     
         1 . A digital dispense system comprising:
 a pipette-fillable fluid cartridge having one or more fluid chambers therein and having an ejection head attached thereto, the ejection head containing a plurality of fluid ejectors thereon, wherein the fluid ejectors are in fluid flow communication with the one or more fluid chambers of the pipette-fillable fluid cartridge; and   a fluid detection circuit disposed on the ejection head and associated with at least one of the plurality of fluid ejectors for signaling the presence or absence of fluid in the one or more fluid chambers.   
     
     
         2 . The digital dispense system of  claim 1 , wherein the fluid detection circuit is selected from the group consisting of (a) a conductivity sense circuit, (b) a thermal sense circuit, and a combination of (a) and (b). 
     
     
         3 . The digital dispense system of  claim 2 , wherein the conductivity sense circuit comprises a first electrode in electrical communication with at least one of the plurality of fluid ejectors, and a second electrode disposed in a fluid flow path to at least one of the plurality of fluid ejectors. 
     
     
         4 . The digital dispense system of  claim 2 , wherein the thermal sense circuit comprises a voltage slope detect circuit for at least one of the plurality of fluid ejectors. 
     
     
         5 . The digital dispense system of  claim 1 , wherein the fluid cartridge comprises two or more discrete fluid chambers. 
     
     
         6 . The digital dispense system of  claim 1 , wherein the ejection head comprises two or more arrays of fluid ejectors thereon and at least one fluid ejector from each of the two or more arrays of fluid ejectors is associated with the fluid detection circuit. 
     
     
         7 . A method for dispensing fluid with a digital dispense system, comprising:
 providing a pipette-fillable fluid cartridge having one or more fluid chambers therein and having an ejection head attached thereto, the ejection head containing a plurality of fluid ejectors thereon, wherein the fluid ejectors are in fluid flow communication with the one or more fluid chambers of the pipette-fillable fluid cartridge; and a fluid detection circuit is disposed on the ejection head and associated with at least one of the plurality of fluid ejectors for signaling the presence or absence of fluid in the one or more fluid chambers;   filling at least one of the one or more fluid chambers with a fluid to be dispensed;   activating a diagnostic function of the digital dispense system to determine if the fluid to be dispensed is present in or absent from the at least one of the one or more fluid chambers; and   initiating a fluid dispense sequence in an absence of an error or warning from the diagnostic function.   
     
     
         8 . The method of  claim 8 , wherein the fluid detection circuit is selected from the group consisting of (a) a conductivity sense circuit, (b) a thermal sense circuit, and a combination of (a) and (b). 
     
     
         9 . The method of  claim 8  wherein the conductivity sense circuit comprises a first electrode in electrical communication with at least one of the plurality of fluid ejectors, and a second electrode disposed in a fluid flow path to at least one of the plurality of fluid ejectors. 
     
     
         10 . The method of  claim 8 , wherein the thermal sense circuit comprises a voltage slope detect circuit for at least one of the plurality of fluid ejectors. 
     
     
         11 . The method of  claim 7 , further comprising modifying the fluid dispense sequence in the presence of an error or warning from the diagnostic function that indicates an incorrect fluid in the at least one of the one or more fluid chambers. 
     
     
         12 . The method of  claim 7 , further comprising modifying the fluid dispense sequence in the presence of an error or warning from the diagnostic function that indicates that fluid is absent from at least one of the one or more fluid chambers. 
     
     
         13 . The method of  claim 7 , further comprising terminating the fluid dispense sequence in the presence of an error or warning from the diagnostic function that indicates that fluid is absent from at least one of the one or more fluid chambers. 
     
     
         14 . A digital dispense system comprising:
 a pipette fillable cartridge having at least one fluid chamber therein and an ejection head in fluid flow communication with the at least one fluid chamber, wherein the ejection head contains a plurality of fluid ejectors and a fluid detection circuit thereon;   a processor disposed in the digital dispense system configured with a fluid detect algorithm, wherein the processor is in electrical communication with the fluid detection circuit for activating an error signal in the absence of fluid; and   a user input device for modifying or terminating a fluid dispense sequence upon error signal activation.   
     
     
         15 . The digital dispense system of  claim 14 , wherein the fluid detect algorithm is programmed to use (a) fluid conductivity data, (b) ejector thermal data, or a combination of (a) and (b) to determine if a fluid is present in the at least one fluid chamber. 
     
     
         16 . The digital dispense system of  claim 15 , wherein the fluid detect algorithm is programmed to (i) use fluid conductivity data initially and to (ii) use ejector thermal data if fluid is not found by (i). 
     
     
         17 . The digital dispense system of  claim 14 , wherein the pipette-fillable cartridge comprises two or more fluid chambers and wherein the fluid detect algorithm is programmed to determine if a fluid is absent from a predetermined one of the two or more fluid chambers. 
     
     
         18 . The digital dispense system of  claim 14 , wherein the fluid detect algorithm is programmed to determine when the at least one fluid chamber runs out of fluid.