Large-area fiber composite with high fiber consistency

Abstract

A method of manufacturing a fiber assembly, the method comprising: (a) providing a plurality of layers, each layer comprising sintered fibers of piezoelectric material aligned substantially parallel; (b) laminating the plurality of layers; and (c) applying a matrix material to the laminated layers to affix the layers and form a fiber assembly.

What is claimed is:  
     
         1 . A method of manufacturing a fiber assembly, said method comprising: 
 providing a plurality of layers, each layer comprising sintered fibers of piezoelectric material aligned substantially parallel;    laminating said plurality of layers; and    applying a matrix material to the laminated layers to affix said layers and form a fiber assembly.    
     
     
         2 . The method of  claim 1 , further comprising: 
 sectioning a portion from said fiber assembly.    
     
     
         3 . The method of  claim 2 , wherein said portion has two opposing surfaces and contains fibers that are substantially normal to said opposing surfaces.  
     
     
         4 . The method of  claim 2 , wherein said portion has two opposing surfaces and contains fiber that are substantially parallel to said opposing surfaces.  
     
     
         5 . The method of  claim 2 , further comprising: 
 applying at least one electrode to each opposing surface.    
     
     
         6 . The method of  claim 5 , wherein a plurality of interigitized electrodes are applied.  
     
     
         7 . The method of  claim 1 , wherein laminating said planar layers comprises interleaving planar layers of varying fiber characteristics.  
     
     
         8 . The method of  claim 7 , wherein said layers of varying fiber characteristics have different fiber concentrations.  
     
     
         9 . The method of  claim 7 , wherein said layers of varying fiber characteristics have fibers of different average diameters.  
     
     
         10 . The method of  claim 7 , wherein a different set of electrodes is applied to said layers of varying fiber characteristics.  
     
     
         11 . The method of  claim 1 , wherein said layers have substantially similar fiber characteristics.  
     
     
         12 . The method of  claim 1 , further comprising poling said sectioned portion.  
     
     
         13 . The method of  claim 1 , wherein said piezoelectric material is at least one of PZT (lead zirconium titanate), lead niobate (PbNbO 6 ), lead titanate (PbTiO 3 ), barium titanate (BaTiO 3 ), sodium bismoth titanate (pure or co-doped), lead-based ceramics doped with lanthanum, tin, or niobium, electrostrictive materials, memory piezoelectric materials, or relaxor materials.  
     
     
         14 . The method of  claim 1 , wherein each opposing side of said portion has an area greater than about 1.5 cm 2 .  
     
     
         15 . The method of  claim 1 , wherein the variation of fiber concentration in no greater than about 20%/cm 3 .  
     
     
         16 . A fiber assembly made from the method of  claim 1 .  
     
     
         17 . A portion made from the method of  claim 2 .  
     
     
         18 . A fiber composite comprising: 
 two opposing surfaces wherein each opposing surface has an area greater than about 1.5 in 2 ;    a plurality of piezoelectric fibers wherein the fiber concentration/cm 3  varies no greater than about 20% of the overall fiber concentration of fiber composite; and    a matrix material binding said fibers.    
     
     
         19 . The fiber composite of  claim 18 , wherein said fibers are normal to said opposing surfaces.  
     
     
         20 . The fiber composite of  claim 18 , wherein said area is no less than about 2.5 in 2.