Patents by Inventor Hengda Derek Liu

Hengda Derek Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20110068500
    Abstract: Provided are molds comprising a substantially concave portion, and a cap portion that is configured for removable attachment to the substantially concave portion and comprises a mandrel formed from a substantially rigid material, wherein the cap portion and the substantially concave portion, when attached, define an internal space having a three-dimensional shape. Among other benefits, the disclosed devices and methods of using such devices provide more uniform and repeatable compaction than conventional molds, and can be used to produce compacted structures having more dimensionally accurate and repeatable surface features, thereby yielding a better, more optimal near net shaped part.
    Type: Application
    Filed: September 8, 2010
    Publication date: March 24, 2011
    Applicant: DEPUY PRODUCTS, Inc.
    Inventors: ANDREW JAMES MARTIN, HENGDA DEREK LIU, JUWAN RIM, JEFFREY A. RYBOLT
  • Publication number: 20090326674
    Abstract: The present invention concerns processes for etching a porous titanium foam or porous titanium alloy foam where a clean, dry foam product is immersed into an aqueous acid solution comprising about 0.5 to about 5 volume percent HF and about 5 to about 20 volume percent HNO3 for a time sufficient to achieve a desired surface roughness and heating the etched foam to remove residual titanates. The etching process increases the porosity at the surface of the foam but the etchant does not penetrate fully into the interior of the foam so that adequate mechanical properties are maintained. The etching process also increases the coefficient of friction at the foam surface. The foam may comprise an open-celled orthopaedic or dental implant, or may comprise a coating on the surface of a substrate.
    Type: Application
    Filed: June 19, 2009
    Publication date: December 31, 2009
    Applicant: DEPUY PRODUCTS, INC.
    Inventors: Hengda Derek Liu, Sophie Xiaofan Yang