Process for manufacturing an integrated membrane of nozzles in mems technology for a spray device and spray device using such membrane

Abstract

A process for manufacturing a membrane of nozzles of a spray device, comprising the steps of laying a substrate, forming a membrane layer on the substrate, forming a plurality of nozzles in the membrane layer, forming a plurality of supply channels in the substrate, each supply channel being substantially aligned in a vertical direction to a respective nozzle of the plurality of nozzles and in direct communication with the respective nozzle.

1 . A process, comprising:
 manufacturing a nozzle membrane, the manufacturing including:   providing a substrate of a first material;   forming a membrane layer of a second material on the substrate;   forming a plurality of nozzles in the membrane layer; and   forming a plurality of supply channels in the substrate, each supply channel being substantially aligned in a vertical direction with a respective nozzle of said plurality of nozzles and in direct communication with the respective nozzle.   
     
     
         2 . The process according to  claim 1 , wherein forming the membrane layer comprises forming the membrane layer distinct from said substrate. 
     
     
         3 . The process according to  claim 1 , wherein forming the membrane layer comprises growing or depositing said second material. 
     
     
         4 . The process according to  claim 3 , wherein said second material is polysilicon. 
     
     
         5 . The process according to  claim 1 , wherein said first material of the substrate is different from said second material of the membrane layer or the first and second material are a same material in different crystalline states. 
     
     
         6 . The process according to  claim 1 , further comprising forming a sacrificial layer between the substrate and the membrane layer, selectively removing said first sacrificial layer, and directly connecting each supply channel with the respective nozzle. 
     
     
         7 . The process according to  claim 6 , wherein forming the sacrificial layer is performed before forming the membrane layer, the process further comprising, before forming the membrane layer, forming trenches in the sacrificial layer by removing selective portions of said sacrificial layer, said forming the membrane layer forming membrane anchorages anchored to the substrate through said trenches. 
     
     
         8 . The process according to  claim 1 , further comprising, before forming the supply channels, digging a back of the substrate and forming a reservoir in said substrate underneath said plurality of nozzles. 
     
     
         9 . The process according to  claim 1 , further comprising forming a plurality of guide channels, each guide channel extending on a respective nozzle of said plurality of nozzles. 
     
     
         10 . The process according to  claim 9  wherein forming the plurality of guide channels comprises:
 after the step of forming the plurality of nozzles, depositing a sacrificial layer on the membrane layer;   selectively removing the sacrificial layer in areas laterally offset with respect to the nozzles;   growing a guide-channel layer on the sacrificial layer;   removing selective portions of the guide-channel layer; and   removing the sacrificial layer and directly connecting each guide channel with the respective nozzle.   
     
     
         11 . A spray device comprising:
 a reservoir having an inner chamber configured so as to contain a liquid substance;   an emission structure coupled to the reservoir for emission of the liquid substance, said emission structure including a nozzle membrane that includes:
 a substrate of a first material; 
 a membrane layer of a second material formed on the substrate; 
 a plurality of nozzles formed through the membrane layer; and 
 a plurality of source channels formed in the substrate and extending through said substrate, the source channels corresponding respectively to the nozzles and being in direct communication with the nozzles, respectively. 
   
     
     
         12 . The spray device of  claim 11 , wherein said membrane layer is distinct from said substrate. 
     
     
         13 . The spray device of  claim 11 , wherein said first material of the substrate is different from the second material of the membrane layer or the first and second material are a same material in different crystalline states. 
     
     
         14 . The spray device according to  claim 11 , wherein said second material is polysilicon. 
     
     
         15 . The spray device of  claim 11 , further comprising;
 an inlet mouth coupled to the inner chamber to enable filling the reservoir; and   an actuator coupled to the reservoir and configured so as to cause ejection of the liquid substance from the reservoir.   
     
     
         16 . The spray device of  claim 15 , wherein the actuator is a piezoelectric actuator. 
     
     
         17 . The spray device of  claim 11 , wherein the source channels extend lengthwise in a direction that is substantially perpendicular to a face of the substrate one which the membrane layer is positioned. 
     
     
         18 . The spray device of  claim 11 , wherein at least a portion of the membrane layer is directly coupled to the substrate via anchorages. 
     
     
         19 . An inhaler, comprising:
 a controller configured to control a release of a liquid; and   a spray device that includes:
 a fluid reservoir configured to store a fluid; and 
 a nozzle membrane coupled to the fluid reservoir and configured to allow ejection of the fluid, the nozzle membrane including:
 a substrate; 
 a membrane layer formed on the substrate; 
 a plurality of nozzles formed through the membrane layer; and 
 a plurality of source channels formed in the substrate and extending through said substrate, the source channels corresponding respectively to the nozzles and being in direct communication with the nozzles, respectively. 
 
   
     
     
         20 . The inhaler of  claim 19 , wherein the nozzle membrane also includes guide channels formed on the membrane layer to guide the ejection of the fluid. 
     
     
         21 . The inhaler of  claim 19 , further comprising:
 a battery to provide energy to the controller; and   a pushbutton to activate control electronics of the controller;   a fluidic module to store a supply of the fluid, the fluidic module being coupled to the fluid reservoir to re-supply the fluid reservoir with the fluid.   
     
     
         22 . The inhaler of  claim 21 , wherein the pushbutton is configured to expose the nozzle membrane when depressed and keep the membrane of nozzles covered when not depressed. 
     
     
         23 . A nozzle membrane for a spray device, the nozzle membrane comprising:
 a substrate;   a membrane layer formed on the substrate;   a plurality of nozzles formed through the membrane layer; and   a plurality of source channels formed in the substrate and extending through said substrate, the source channels corresponding respectively to the nozzles and being in direct communication with the nozzles, respectively.   
     
     
         24 . The nozzle membrane of  claim 23 , wherein the source channels extend lengthwise in a direction that is substantially perpendicular to a face of the substrate one which the membrane layer is positioned. 
     
     
         25 . The nozzle membrane of  claim 23 , wherein at least a portion of the membrane layer is directly coupled to the substrate via anchorages.