3d piezoelectric polymer materials and devices

Abstract

Methods, systems, and devices are disclosed for fabricating 3D piezoelectric materials. In one aspect, a method includes photopolymerizing a selected portion of a two dimensional plane in a sample of a photoliable polymer solution containing piezoelectric nanoparticles to form a layer of a piezoelectric material, the photopolymerizing including directing light from a light source based on a pattern design in the selected portion of the photoliable polymer solution; and moving one or both of the sample and the directed light to photopolymerize another selected portion of another two dimensional plane in the sample to form another layer of the piezoelectric material.

What is claimed are techniques and structures as described and shown, including: 
     
         1 . A method to fabricate a piezoelectric material, comprising:
 photopolymerizing a selected portion of a two dimensional plane in a sample of a photoliable polymer solution containing piezoelectric nanoparticles to form a layer of a piezoelectric material, the photopolymerizing including directing light from a light source based on a pattern design in the selected portion of the photoliable polymer solution; and   moving one or both of the sample and the directed light to photopolymerize another selected portion of another two dimensional plane in the sample to form another layer of the piezoelectric material.   
     
     
         2 . The method as in  claim 1 , wherein the formed piezoelectric material is formed into a predetermined shape based on a pattern design. 
     
     
         3 . The method as in  claim 1 , wherein the photoliable polymer solution includes at least one of a poly(ethylene glycol diacrylate), poly(methyl methacrylate), poly(acrylic acid), or poly(lactic acid). 
     
     
         4 . The method as in  claim 1 , wherein the piezoelectric nanoparticles include one or more of barium titanate (BTO), lead magnesium niobate-lead titanate (PMN-PT), lead zirconate titanate (PZT), zinc oxide (ZnO), or sodium niobate (NaNbO 3 ). 
     
     
         5 . The method as in  claim 1 , wherein the light source includes at least one of laser or light emitting diode (LED). 
     
     
         6 . The method as in  claim 1 , wherein the light source emits ultraviolet light. 
     
     
         7 . The method as in  claim 1 , wherein the formed piezoelectric material exhibits properties including biocompatible, mechanically flexible, size scalable, shape tunable, directly piezoelectrically responsive, or conversely piezoelectrically responsive. 
     
     
         8 . The method as in  claim 1 , further comprising:
 adding a linker molecule to the photoliable polymer solution to covalently link the piezoelectric nanoparticles to a polymer matrix in the photoliable polymer solution.   
     
     
         9 . The method as in  claim 8 , wherein the linker molecule includes 3-trimethoxysilylpropyl methacrylate (TMSPM). 
     
     
         10 . The method as in  claim 8 , wherein the linker molecule includes 3-trimethoxysilylpropyl acrylate (TMSPA). 
     
     
         11 . The method as in  claim 1 , further comprising:
 adding a mechanical-to-electrical enhancer to the photoliable polymer matrix wherein the mechanical-to-electrical enhancer includes carbon nanotubes (CNTs).   
     
     
         12 . The method as in  claim 1 , further comprising:
 activating the piezoelectric material by applying an electric field larger than a coercive field of the piezoelectric nanoparticles.   
     
     
         13 . A device comprising a piezoelectric material structure which includes:
 a three-dimensional structure; and   a plurality of piezoelectric nanoparticles grafted to the three-dimensional structure; and   wherein the piezoelectric material structure is operable to generate an electric charge in response to an applied mechanical force and to generate a mechanical force in response to an applied electrical signal; and   wherein the piezoelectric material structure is fabricated using a light-assisted polymerization technique by causing crosslinking in a photoliable polymer solution.   
     
     
         14 . The device as in  claim 13 , further comprising:
 a linker molecule that covalently links the piezoelectric nanoparticles to a polymer matrix in the piezoelectric material structure.   
     
     
         15 . The device as in  claim 13 , wherein the piezoelectric nanoparticles include one or more of barium titanate (BTO), lead magnesium niobate-lead titanate (PMN-PT), lead zirconate titanate (PZT), zinc oxide (ZnO), or sodium niobate (NaNbO 3 ). 
     
     
         16 . The device as in  claim 13 , wherein the piezoelectric material structure exhibits biocompatible, mechanically flexible, size scalable, shape tunable, directly piezoelectrically responsive, or conversely piezoelectrically responsive. 
     
     
         17 . The device as in  claim 13 , further comprising:
 a linker molecule that covalently links the piezoelectric nanoparticles to a polymer matrix in the piezoelectric material structure.   
     
     
         18 . The device as in  claim 17 , wherein the linker molecule includes 3-trimethoxysilylpropyl methacrylate (TMSPM). 
     
     
         19 . The device as in  claim 17 , wherein the linker molecule includes 3-trimethoxysilylpropyl acrylate (TMSPA). 
     
     
         20 . The device as in  claim 13 , further comprising a mechanical-to-electrical enhancer, wherein the mechanical-to-electrical enhancer includes carbon nanotubes (CNTs). 
     
     
         21 . The device as in  claim 13 , comprising a biometric sensor based on the piezoelectric material structure operable to convert mechanical stress to electrical signals. 
     
     
         22 . The device as in  claim 13 , comprising a sensing circuit coupled to the piezoelectric material structure to receive an electrical signal produced by the piezoelectric material structure in response to a mechanical stress applied thereto. 
     
     
         23 . The device as in  claim 13 , comprising a microelectromechanical or nanoelectromechanical device based on the piezoelectric material structure operable to convert one or more of mechanical stress to electrical signals or electrical signals to mechanical stress. 
     
     
         24 . The device as in  claim 13 , wherein the device is a wearable device operable to convert mechanical stress to electrical signals to charge a battery. 
     
     
         25 . The device as in  claim 13 , comprising an acoustic speaker based on the piezoelectric material structure operable to convert electrical signals to mechanical stress for audio sound production. 
     
     
         26 . The device as in  claim 13 , comprising an acoustic imaging system based on the piezoelectric material structure operable to convert mechanical stress to electrical signals in receiving ultrasound image signals for imaging reconstruction or to convert electrical signals to mechanical stress in transmitting ultrasound signal for imaging. 
     
     
         27 . A method to fabricate a device based on a piezoelectric material, comprising:
 directing an optical beam to a photoliable polymer solution containing piezoelectric nanoparticles;   modulating and controlling the optical beam in a way that causes photopolymerizing of selected portions of the photoliable polymer solution to form a three dimensional piezoelectric material structure;   forming one or more electrical contacts to the three dimensional piezoelectric material structure to construct the device to apply an electrical control to the three dimensional piezoelectric material structure, or to receive an electrical response from the three dimensional piezoelectric material structure under a stress.   
     
     
         28 . The method as in  claim 27 , wherein the optical beam is modulated by a two-dimensional spatial light modulator to carry a spatial pattern that forms part of the shape of the three dimensional piezoelectric material structure. 
     
     
         29 . The method as in  claim 28 , wherein the two-dimensional spatial light modulator includes a digital micromirror-array device. 
     
     
         30 . The method as in  claim 28 , wherein the part of the shape of the three dimensional piezoelectric material structure is a layer of the three dimensional piezoelectric material structure, and
 wherein the modulating and controlling the optical beam include modulating the optical beam at to carry a spatial pattern of one layer of various layers of the three dimensional piezoelectric material structure and to carry different spatial patterns of different layers of the three dimensional piezoelectric material structure at different times to cause crosslinking at different depths of the photoliable polymer solution.   
     
     
         31 . The method as in  claim 27 , wherein the optical beam is at a UV wavelength that can directly cause crosslinking in the photoliable polymer solution. 
     
     
         32 . The method as in  claim 27 , wherein the optical beam is at a longer wavelength than a UV wavelength that can directly cause crosslinking in the photoliable polymer solution, and the controlling of the optical beam includes controlling an optical power of the optical beam at a selected location in the photoliable polymer solution to cause a nonlinear optical two-photon absorption that triggers crosslinking in the photoliable polymer solution. 
     
     
         33 . The method as in  claim 27 , wherein the photoliable polymer solution includes at least one of a poly(ethylene glycol diacrylate), poly(methyl methacrylate), poly(acrylic acid), or poly(lactic acid). 
     
     
         34 . The method as in  claim 27 , wherein the piezoelectric nanoparticles include one or more of barium titanate (BTO), lead magnesium niobate-lead titanate (PMN-PT), lead zirconate titanate (PZT), zinc oxide (ZnO), or sodium niobate (NaNbO 3 ).