Fabrication of ceramic microstructures from polymer compositions containing ceramic nanoparticles
AssigneeSandia Corporation
InventorsAlfredo Martin Morales, Z. John Zhang, Douglas Chinn
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Abstract
A method is provided for fabricating ceramic microstructures, i.e., microcomponents of micron or submicron dimensions. A polymer composition is prepared containing a polymer, typically a thermally or chemically curable polymer, and nanometer size (1 to 1000 nm in diameter) ceramic particles. A mold, such as a lithographically patterned mold, preferably a LIGA mold, is filled with the polymer composition and the polymer is then cured or otherwise hardened. The elevated segments of the mold are then removed. The surface-attached ceramic microstructures so provided may then be removed from the substrate and, if desired, pyrolyzed and sintered.
Claims53
A method for preparing ceramic microstructures, comprising:
- (a) providing, as a mold, a substrate having a pattern on its surface, said pattern comprised of chemically removable elevated segments and corresponding voids therebetween;
- (b) applying a curable polymer composition to the substrate surface and pressing the composition into the voids of the surface pattern, said curable polymer composition comprising ceramic nanoparticles and a curable binder polymer;
- and
- (c) curing the polymer to provide ceramic microstructures in said voids.
A method for preparing ceramic microstructures, comprising:
- (a) providing a lithographically patterned mold comprising a substrate having a pattern on its surface, said pattern comprised of chemically removable elevated segments and corresponding voids therebetween, said voids having a diameter of less than about 100 microns in diameter;
- (b) applying a curable polymer composition to the substrate surface and pressing the composition into the voids of the surface pattern, said curable polymer composition comprising a paste of ceramic nanoparticles having a diameter in the range of approximately 1 nm to 1000 nm, a curable binder polymer selected from the group consisting of vinyl polymers, acrylic polymers, silicon-containing polymers, epoxy resins, and copolymers and blends thereof, and a solvent for the curable binder polymer, wherein the ceramic nanoparticles represent approximately 15 wt. % to 95 wt. % of the composition and the curable polymer represents approximately 5 wt. % to 30 wt. % of the composition;
- (c) curing the polymer to provide ceramic microstructures in said voids;
- and
- (d) removing the elevated segments to provide said ceramic microstructures on the substrate surface.
A method for preparing ceramic microstructures permanently affixed to a substrate, comprising:
- (a) providing a substrate having a substantially planar surface and a recess therein extending from the substrate surface into the substrate interior, wherein the recess is shaped such that the width of the recess at the substrate surface is smaller than the width of the recess in the substrate interior;
- (b) applying a curable polymer composition to the substrate surface and pressing the composition into the recess, said polymer composition comprising a curable binder polymer, ceramic nanoparticles and a solvent for the binder polymer, while allowing a portion of the composition to remain on the substrate surface above the recess;
- and
- (c) curing the binder polymer to provide a ceramic microstructure having a first segment in said recess and conforming in shape thereto, and a second segment above the substrate surface.
A method for preparing ceramic microstructures, comprising:
- (a) providing, as a mold, a substrate having a pattern on its surface, said pattern comprised of chemically removable elevated segments and corresponding voids therebetween;
- (b) forming a paste of a binder polymer, ceramic nanoparticles, and a solvent for said polymer;
- (c) applying the paste to the substrate surface and pressing the paste into the voids of the surface pattern;
- and
- (c) removing the solvent to provide ceramic microstructures in said voids.
A ceramic microstructure comprising a compressed solid of:
- a matrix of a cured polymer;
- and ceramic nanoparticles dispersed throughout the matrix, wherein the aspect ratio of the microstructure is greater than about 20:1.
Dependencies are inferred from the claim text.