Electrolysis recombination mask and related methods

Abstract

A recombination mask integrated onto an electrolysis chip tunes electrolysis parameters by masking off portions of the electrodes exposed to an electrolyte solution. This prevents electrolysis gases from reaching the catalyst on the electrodes and recombining.

1 . A device for administering a liquid, the device comprising:
 a housing;   within the housing, a pump assembly including a reservoir, an electrolytic forcing mechanism and a cannula for conducting liquid from the reservoir to an ejection site exterior to the housing in response to pressure applied by the forcing mechanism; and   internal to the forcing mechanism, an electrolyte reservoir and, therein, an electrode assembly comprising (i) at least two electrodes and (ii) over a portion of at least one of the electrodes, a gas-impermeable mask.   
     
     
         2 . The device of  claim 1 , wherein the mask is sized and shaped so that a ratio of masked to unmasked electrode portions achieves a target operating ratio of gas recombination to gas generation. 
     
     
         3 . The electrolytic pump of  claim 2 , wherein the electrodes are disposed on an electrolysis chip. 
     
     
         4 . The electrolytic pump of  claim 1 , wherein the electrodes comprise at least one of platinum, gold, or silver on parylene, ceramic, or a biocompatible insulator. 
     
     
         5 . The electrolytic pump of  claim 1 , wherein the electrodes act as a recombination catalyst and further comprising an additional recombination catalyst. 
     
     
         6 . The device of  claim 1 , wherein at least a portion of the mask structure is bonded to the electrodes with an epoxy. 
     
     
         7 . The device of  claim 1 , wherein the mask structure comprises PEEK, ceramic, aluminum. 
     
     
         8 . The device of  claim 1 , further comprising a spacer having a height that defines a height of the electrolyte reservoir. 
     
     
         9 . The device of  claim 8 , wherein the spacer surrounds and is not bonded to the electrodes. 
     
     
         10 . A method of manufacturing a device for administering a liquid, the device comprising a housing and, within the housing, a pump assembly including a reservoir, a gas-driven forcing mechanism and a cannula for conducting liquid from the reservoir to an ejection site exterior to the housing in response to pressure applied by the forcing mechanism, and internal to the pumping mechanism, an electrolyte reservoir, the method comprising the steps of:
 providing at least two electrodes;   masking a portion of at least one of the electrodes with a gas-impermeable material; and   introducing the electrodes into the electrolyte reservoir, whereby an exposed portion of the electrodes is patterned to achieve a target operating ratio of gas recombination to gas generation in the reservoir.   
     
     
         11 . The method of  claim 10 , wherein the masking step comprises depositing the gas-impermeable material onto at least one of the electrodes through a pattern template. 
     
     
         12 . The method of  claim 11 , wherein the gas-impermeable material is applied by chemical vapor deposition. 
     
     
         13 . The method of  claim 10 , wherein the masking step comprises depositing the gas-impermeable material onto at least one of the electrodes by pointwise printing in a predetermined pattern. 
     
     
         14 . The method of  claim 10 , wherein the masking step comprising adhering a gas-impermeable material onto at least one of the electrodes. 
     
     
         15 . The method of  claim 10 , further comprising the step of incorporating a spacer onto a non-electrode portion of the electrolyte reservoir.