Nanostructured hydroxyapatite coating for dental and orthopedic implants

\u27A high-strength coating for dental and orthopedic implants utilizing hydroxyapatite (HAp) nanoparticles provides for a high level of osseointegration through a range of surface pore sizes in the micro- to nanoscale. Zinc oxide (ZnO) nanoparticles may be incorporated with the HAp nanoparticles to form a composite coating material, with ZnO providing infection resistance due to its inherent antimicrobial properties. A textured surface, consisting of islands of roughly square coating structures measuring about 250 .mu.m on a side, with spacing of 50-100 .mu.m therebetween, may further promote the osseointegration and antimicrobial properties of the implant coating

Dielectric nanolubricant compositions

A dielectric nanolubricant composition is provided. The dielectric nanolubricant composition includes a nano-engineered lubricant additive dispersed in a base. The nano-engineered lubricant additive may include a plurality of solid lubricant nanostructures having an open-ended architecture and an organic, inorganic, and/or polymeric medium intercalated in the nanostructures and/or encapsulate nanostructures. The base may include a grease or oil such as silicone grease or oil, lithium complex grease, lithium grease, calcium sulfonate grease, silica thickened perfluoropolyether (PFPE) grease or PFPE oil, for example. This dielectric nanolubricant composition provides better corrosion and water resistance, high dielectric strength, longer material life, more inert chemistries, better surface protection and asperity penetration, no curing, no staining, and environmentally friendly, compared to current products in the market

A Comparative Study on Machining Capabilities of Wet and Dry Nanoscale Electro-machining

Presently, the nano scale electro-machining (nano-EM) process has been demonstrated in both the liquid and air dielectric mediums, which are known as wet and dry nano-EM respectively. In the current study, two important aspects of the nano-EM have been investigated: the minimum possible feature dimension and mass fabrication capability of nano-EM. Firstly, the investigation has been done on the capability of machining graphene at atomic scale with focus on obtaining smallest possible nano-feature using the wet nano-EM. Secondly, the ability of the nano-EM process for the fabrication of arrays of nano-holes has been investigated using dry nano-EM. It was found that nano-features of 3 to 4 nm could be machined in graphene surfaces revealing the atomic arrangement of carbon using the wet nano-EM process. The dry nano-EM was found to be capable of fabricating arrays of nano-features making it more suitable for mass fabrication. The field induced evaporation of materials from the tool during dry nano-EM retained the quality of tool electrode, thus making the process capable of fabricating more than 100 nano features in a single step. It was found that the material removal mechanism influenced the machining capability of the process. The mechanism of material removal in the wet nano-EM was associated with the dielectric breakdown of liquid n-decane generating intense heat for ionization, evaporation, and melting of materials. On the other hand, the material removal mechanism of dry nano-EM was associated with the breakdown of air, which generated intense heat at the gap between the nano-EM tool and the workpiece causing localized ionization and evaporation

A Comparative Study on Machining Capabilities of Wet and Dry Nanoscale Electro-machining

Presently, the nano scale electro-machining (nano-EM) process has been demonstrated in both the liquid and air dielectric mediums, which are known as wet and dry nano-EM respectively. In the current study, two important aspects of the nano-EM have been investigated: the minimum possible feature dimension and mass fabrication capability of nano-EM. Firstly, the investigation has been done on the capability of machining graphene at atomic scale with focus on obtaining smallest possible nano-feature using the wet nano-EM. Secondly, the ability of the nano-EM process for the fabrication of arrays of nano-holes has been investigated using dry nano-EM. It was found that nano-features of 3 to 4 nm could be machined in graphene surfaces revealing the atomic arrangement of carbon using the wet nano-EM process. The dry nano-EM was found to be capable of fabricating arrays of nano-features making it more suitable for mass fabrication. The field induced evaporation of materials from the tool during dry nano-EM retained the quality of tool electrode, thus making the process capable of fabricating more than 100 nano features in a single step. It was found that the material removal mechanism influenced the machining capability of the process. The mechanism of material removal in the wet nano-EM was associated with the dielectric breakdown of liquid n-decane generating intense heat for ionization, evaporation, and melting of materials. On the other hand, the material removal mechanism of dry nano-EM was associated with the breakdown of air, which generated intense heat at the gap between the nano-EM tool and the workpiece causing localized ionization and evaporation

A comparative study of the dry and wet nano-scale electro-machining

In recent years, a nano-electromachining (nano-EM) process based on a scanning tunneling microscope (STM) platform has been demonstrated. Nano-EM is capable of machining nano-features, under both, liquid dielectric (wet nano-EM) and air dielectric (dry nano-EM) media. The objective of this paper is to present a comparative study between the wet and dry nano-EM processes based on process mechanism, machining performance, consistency and dimensional repeatability of these two processes. The comparison of the two processes has been conducted at near field nano-EM, where the gap between the tool electrode and workpiece is 2 nm and the machining is performed at room temperature and pressure (macroscopically). The major differences in the process mechanism are due to the media at dielectric interface, the breakdown field strength and breakdown characteristics of two dielectrics and therefore, the material removal mechanism. It is reported that the material removal mechanism of wet nano-EM is associated with field emission-assisted avalanche in nano-confined liquid dielectric, whereas, the material removal mechanism in dry nano-EM is associated with field-induced evaporation of material. The differences have also been observed in the machining performance, dimensions of the machined features and repeatability of the nanoscale machined features. The self-tip-sharpening process with the continuation of machining has added several advantages to dry nano-EM over wet nano-EM in terms of dimensions of the nanoscale features, repeatability and machining performance

Method of planarizing polycrystalline diamonds, planarized polycrystalline diamonds and products made therefrom

A method of planarizing a diamond film which generally includes orifices in the surface is described. The method includes first polishing the diamond film surface to reduce the surface roughness. A filler material is applied to the surface of the film to fill the orifices in the film. The film is polished to remove excess filler material and expose the diamond film surface. Also disclosed are planarized diamond films diamond substrate having a polished surface of both diamond and filler material and a variation in thickness of less than 8 percent

Nanoparticle compositions and methods for making and using the same

A composition that includes solid lubricant nanoparticles and an organic medium is disclosed, as well as nanoparticles that include layered materials. Methods of producing a nanoparticle by milling layered materials and of making a lubricant are provided. The method includes milling layered materials to form nanoparticles and incorporating the nanoparticles into a base to form a lubricant

Polishing of CVD-Diamond Substrates Using Reactive Ion Etching

Multichip modules (MCM)have proved to be a viable packaging technology for achieving small size and high performance. By their nature, MCMs typically integrate multiple bare die into a module that can be the plastic or ceramic package. As a result, the MCMrequires an efficient mechanism for removing excess heat. Diamond with its excellent thermal conductivity, is the ideal choice as a substrate material for these applications. Chemical vapor deposited (CVD) diamond substrates makes possible the practical realization of a novel diamond based 3-D MCM. However, the diamond films grown by CVD technique are polycrystalline and have non-uniform filmroughness and randomly faceted crystals. These non-planar surfaces reduce the diamond\u27s thermal management efficiency. Therefore, itbecomes imperative that the asdeposited diamond films be polished for use inMCMs. Chemical assisted mechanical polishing (CAMP) technique has been developed at HiDEC,University of Arkansas. In this technique diamond is lapped against an alumina plate under a load in the presence of certain chemicals. Although CAMP technique reduces the lapping time considerably, stillnewer techniques must be developed to reduce polishing cost further. We are currently using reactive ion etching (RIE) to substantially reduce the polishing time. Preliminary studies using reactive ion etching showed etch rates of 500 - lOOOA/min at low pressures. These etched films showed a considerably higher polishing rate (using CAMP technique) than the nonetched films. Changes in the morphology and structure of the diamond films due to etching and polishing were characterized by scanning electron microscopy (SEM), Dektak profilometer and Raman spectroscopy. This paper presents a systematic study ofRIEand CAMP of CVD-diamond substrates

Method of electroplating a substrate, and products made thereby

Disclosed is an electroplating method and products made therefrom, which in one embodiment includes using a current density to form a conductive metal layer having a surface roughness no greater than the surface roughness of the underlying member. In another embodiment of electroplating a substrate surface having peaks and valleys, the method includes electroplating a conductive metal onto the peaks to cover the peaks with the conductive metal, and into the valleys to substantially fill the valleys with the conductive metal

Methods and apparatus for making coatings using electrostatic spray

Describe methods for creating coatings composed of a single material or a composite of multiple materials, beginning with ESC to deposit the base layer and then using other methods for the binding step beyond CVI. Also, for certain materials and applications, some pre-processing or pre-treatment of the coating materials is necessary prior to deposition in order to achieve a satisfactory coating. This application discloses methods for pre-deposition treatment of materials prior to ESC deposition. It also discloses methods for post-processing that provide additional functionality or performance characteristics of the coating. Finally, this application discloses certain apparatus and equipment for accomplishing the methods described