Piezoelectric pump and fluid transferring system

Abstract

To provide a piezoelectric pump including: a structure including a piezoelectric element and a support member that supports the piezoelectric element; and a first substrate and a second substrate that sandwich the structure, wherein the piezoelectric pump has: a pump chamber surrounded by the second substrate and the structure; and a first opening and a second opening that are communicated with the pump chamber, and wherein a space is provided so that the structure flexes in a direction opposite to the pump chamber according to an operation of the piezoelectric element.

1 . A piezoelectric pump comprising:
 a structure including a piezoelectric element and a support member that supports the piezoelectric element; and   a first substrate and a second substrate that sandwich said structure,   wherein the piezoelectric pump has: a pump chamber surrounded by said second substrate and said structure; and a first opening and a second opening that are communicated with said pump chamber, and   wherein a space is provided so that said structure flexes in a direction opposite to said pump chamber according to an operation of the piezoelectric element.   
   
   
       2 . The piezoelectric pump according to  claim 1 , wherein the piezoelectric pump has a void surrounded by said first substrate and said structure. 
   
   
       3 . The piezoelectric pump according to  claim 2 , wherein at least one of said piezoelectric element and said support member has a constriction in at least one of an in-plane direction and a thickness direction of said piezoelectric element. 
   
   
       4 . The piezoelectric pump according to  claim 1 , wherein said structure includes two or more piezoelectric elements arranged in a flow direction of a fluid, and one support member that supports said two or more piezoelectric elements, and
 wherein the piezoelectric pump has a void surrounded by said first substrate and said structure.   
   
   
       5 . The piezoelectric pump according to  claim 4 , wherein said support member is a thin film, a part of a main surface of said support member facing said pump chamber having a planar shape in which two or more circular surfaces are partially overlapped with each other, and
 wherein each of said two or more piezoelectric elements is a thin film that is supported on the two or more circular surfaces and has a circular main surface.   
   
   
       6 . The piezoelectric pump according to  claim 4 , wherein each of said two or more piezoelectric elements includes a piezoelectric body and one pair of electrodes sandwiching said piezoelectric body, and has three or more wires led out alternately from said pair of electrodes along the flow direction of the fluid. 
   
   
       7 . The piezoelectric pump according to  claim 1 , wherein said piezoelectric element includes a displacement part that is displaced by application of a voltage, and a fixed part that is fixed by being directly or indirectly sandwiched between said first substrate and said second substrate, and
 wherein from a state where said first substrate is joined to said structure, a part of said first substrate facing said displacement part and a surrounding part of said support member surrounding a periphery of said displacement part is removed so as to expose said displacement part and said surrounding part.   
   
   
       8 . The piezoelectric pump according to  claim 7 , wherein said piezoelectric element includes a first electrode, a piezoelectric body, and a second electrode that are laminated in the stated order in a direction from said first substrate to said second substrate, and
 wherein a first laminate composed of said first electrode and said piezoelectric body has a smaller product of Young's modulus and thickness than said second electrode.   
   
   
       9 . The piezoelectric pump according to  claim 8 , wherein said piezoelectric element further includes a hard layer on a surface of said second electrode facing said second substrate, and
 wherein said first laminate has a smaller product of Young's modulus and thickness than a second laminate composed of said second electrode and said hard layer.   
   
   
       10 . The piezoelectric pump according to  claim 9 , wherein said hard layer is made of at least one metal selected from the group consisting of chromium, tungsten, tantalum, and platinum. 
   
   
       11 . A fluid transferring system comprising a first valve unit, a piezoelectric pump unit, and a second valve unit in the stated order along a flow direction of a fluid,
 wherein said piezoelectric pump unit includes: a first structure including a first piezoelectric element and a first support member that supports said first piezoelectric element; and a first substrate and a second substrate that sandwich said first structure, said piezoelectric pump unit has: a pump chamber surrounded by said second substrate and said first structure; and a first opening and a second opening that are communicated with said pump chamber, and a space is provided so that said first structure flexes in a direction opposite to said pump chamber according to an operation of said first piezoelectric element,   wherein said first valve unit includes: a second structure including a second piezoelectric element and a second support member that supports said second piezoelectric element; and said first substrate and said second substrate that sandwich said second structure, and said first valve unit is opened or closed by a part of said second structure becoming out of or into contact with a part of said first substrate or said second substrate according to an operation of said second piezoelectric element, and   wherein said second valve unit includes: a third structure including a third piezoelectric element and a third support member that supports said third piezoelectric element; and said first substrate and said second substrate that sandwich said third structure, and said second valve unit is opened or closed by a part of said third structure becoming out of or into contact with a part of said first substrate or said second substrate according to an operation of said third piezoelectric element.