Mems microtensiometer

Abstract

A device for measuring a chemical potential of a fluid in a plant tissue includes a cavity disposed within a sensor body as a liquid reservoir. The cavity is configured for containing therein a liquid, and the cavity including at least one opening. At least two porous membrane layers are positioned at least in part over the at least one opening of the cavity for selectively allowing water transfer between the plant fluid and the liquid in the cavity. At least one pressure sensor is configured for detecting changes in pressure of the liquid in the cavity. The changes are related to a chemical potential of the fluid in the plant tissue.

1 - 18 . (canceled) 
     
     
         19 . A device for measuring a chemical potential of a fluid in a plant tissue, said device comprising:
 a cavity disposed within a sensor body as a liquid reservoir, said cavity configured for containing therein a liquid, said cavity comprising at least one opening;   at least two porous membrane layers positioned at least in part over said at least one opening of said cavity for selectively allowing water transfer between the plant fluid and the liquid in the cavity; and   at least one pressure sensor configured for detecting changes in pressure of the liquid in said cavity, said changes are related to a chemical potential of the fluid in the plant tissue.   
     
     
         20 . The device according to  claim 19 , wherein at least one of said at least two porous membrane layers comprises a reverse osmotic membrane or a nanoporous membrane. 
     
     
         21 . The device according to  claim 19 , wherein said at least one pressure sensor comprises at least one piezoelectric transducer sensor or at least one strain gauge sensor. 
     
     
         22 . The device according to  claim 19 , wherein said device comprises a Micro Electro-Mechanical System (MEMS). 
     
     
         23 . The device according to  claim 19 , wherein said cavity is configured for being hydraulically connected to a vascular conduit of the plant, via a space of the plant tissue, wherein said chemical potential comprises a measurement of plant sap water conducted through said vascular conduit. 
     
     
         24 . The device according to  claim 19 , wherein said cavity comprises a flattened shape forming a cavity for containing the liquid therein and a single opening, wherein said at least two porous membrane layers are located over said opening of said cavity at an internal or external side thereof. 
     
     
         25 . The device according to  claim 19 , further comprising a borosilicate glass disposed at least in part between said at least two porous membrane layers. 
     
     
         26 . The device according to  claim 19 , wherein said cavity is configured such that there is a direct contact between the plant fluid and the liquid therein said cavity, via said at least two porous membrane layers 
     
     
         27 . A method for measuring fluid potential in a plant tissue, said method comprising the steps of:
 providing a device for measuring a chemical potential of a fluid in a plant tissue, said device comprising: a cavity disposed in a sensor body as a liquid reservoir, said cavity configured for containing therein a liquid, said cavity comprising at least one opening, at least two porous membrane layers positioned at least over said at least one opening of said cavity for selectively allowing water transfer between the plant fluid and the liquid in the cavity, and at least one pressure sensor configured for detecting changes in pressure of the liquid in said cavity, said changes related to a chemical potential of the fluid in the plant tissue;   placing at least part of said measuring device inside the plant, wherein said at least two porous membrane layers are configured to selectively allow transfer of water therethrough, while blocking transfer of other ingredients in the plant fluid;   sensing changes in pressure caused due to an osmotic based flow of fluids into or out of said cavity caused to equilibrate the chemical potential of the plant tissue fluid and the liquid in the cavity; and   outputting pressure sensor data indicative of the sensed pressure, said changes related to the fluid potential of the plant tissue.   
     
     
         28 . The method according to  claim 27 , further comprising the steps of:
 a) receiving outputted sensor data from said at least one pressure sensor; and   b) calculating the fluid potential in said plant according to the sensed pressure.   
     
     
         29 . The method according to  claim 27 , wherein said measuring device is placed in proximity to at least one vascular conduit of the plant or is inserted to the tissue of a stem of the plant. 
     
     
         30 . The method according to  claim 27 , wherein said cavity is configured such that there is a direct contact between the plant fluid and the liquid therein said cavity, via said at least two porous membrane layers. 
     
     
         31 . The method according to  claim 27 , wherein said measuring device creates a liquid continuum with the plant tissue.