Abstract:
Anti-microbial coatings and powders and method of forming same on medical devices are provides. The coatings are preferably formed by depositing an anti-microbial biocompatible metal by vapour deposition techniques to produce atomic disorder in the coating such that a sustained release of metal ions sufficient to produce an anti-microbial effect is achieved. Preferred deposition conditions to achieve atomic disorder include a lower than normal substrate temperature, and one or more of a higher than normal working gas pressure and a lower than normal angle of incidence of coating flux. Anti-microbial powders formed by vapour deposition or altered by mechanical working to produce atomic disorder are also provided. The anti-microbial effect of the coatings or powders may be further activated or enhanced by irradiating with a low linear energy transfer form of radiation such as gamma radiation. Novel anti-microbial silver materials are defined, characterized by having a positive rest potential, a Trec/Tm less than 0.33, and a grain size less than 200 nm. Anti-microbial fine grain or nanocrystalline materials are provided, together with methods of preparation, wherein the anti-microbial metal if deposited in a matrix with atoms or molecules of a different material such as other biocompatible metals (ex. Ta), trapped or absorbed oxygen, or compounds of anti-microbial metals or biocompatible metals (ex. Ag0 or TaO). The invention also extends to a method of producing an anti-microbial effect with silver materials that form complex silver ions other than Ag?+, Ag2+ and Ag3+¿.
Abstract:
The present invention relates to a method of producing an anti-microbial effect in an alcohol or water based electrolyte, comprising:
(a) preparing a silver material such that it forms complex silver ions other than Ag + , Ag 2+ or Ag 3+ , in an amount so as to produce an anti-microbial effect in contact with an alcohol or water-based electrolyte that is greater than that produced by an equivalent amount of silver as Ag + ; and (b) bringing the silver material into contact with the alcohol or electrolyte to be treated so as to cause the release of the complex silver ions.
Abstract:
An improved process for the preparation of metallized ceramic substrates having a metal layer ranging from ten to two hundred microns in thickness, and having enhanced adhesion strength is provided. The process involves, in combination, a novel method for conditioning the ceramic substrate and the application of a thin intermediate layer of electrolessly and optionally, electrolytically, deposited metal prior to electrolytic metal deposition of an outer metallized layer.
Abstract:
A process is described of forming an electroluminescent (EL) display panel formed from an EL laminate having a phosphor layer (22) sandwiched between a front and a rear set of intersecting address lines (14,24), the rear address lines (12) being formed on a substrate (12) having sufficient rigidity to support the laminate and the phosphor layer being separated from the rear address lines by one or more dielectric layers (18,20); the process comprising the steps of: (a) providing a substrate formed with a plurality of through holes (32) patterned to be proximate the ends of the address lines to be subsequently formed; (b) forming a conductive path through each of the through holes in the substrate to provide for electrical connection of each address line, subsequently formed, to the voltage driving circuit (30); (c) forming the rear spaced address lines (14) on the substrate (12), one end of each line ending adjacent a through hole (32) and being electrically connected with the conductive path therethrough; (d) forming a dielectric layer (18,20) on the rear address lines (14); (e) forming the phosphor layer (22) above the dielectric layer: (f) optionally forming a transparent dielectric layer on the phosphor layer; and then (g) forming the front spaced address lines (24) on the underlying phosphor or transparent dielectric layer, one end of each line ending adjacent a through hole and being electrically connected with the conductive path therethrough. The invention also describes a method for laser scribing a pattern in a planar laminate (preferably an EL panel) having at least one overlying layer (e.g. a transparent layer for forming the front address lines (24)) and at least one underlying layer (e.g. a phosphor layer (22)); the method comprising: applying a focused laser beam on the overlying layer side of the laminate, said laser beam having a wavelength which is substantially unabsorbed by the overlying layer (24) but which is absorbed by the underlying layer (22), such that at least a portion of the underlying layer (22) is directly ablated and the overlying layer (24) is indirectly ablated throughout its thickness (thereby forming individual front address lines (24)).
Abstract:
A thin film diagnostic device capable of detecting the presence of a specific organic material in a sample solution. The device comprises a layer of an anodizable colour-generating metal (12) (e.g. tantalum), a porous anodic film (14) containing aluminum oxide overlying the colour generating metal (12), and a reagent capable of binding with the specific organic material forming a coating (17) on the anodic film. The porous anodic film (14) and the coating (17) have a combined thickness such that a colour change is produced when the specific organic material binds to the reagent to form a second coating (22). The device can be used to test for biological or synthetic products in samples taken from patients or other sources.
Abstract:
The invention provides a microwave susceptor bed useful for sintering ceramics, ceramic composites and metal powders. The susceptor bed comprises granules of a major amount of a microwave susceptor material, and a minor amount of a refractory parting agent, either dispersed in the susceptor material, or as a coating on the susceptor material. Alumina is the preferred susceptor material. Carbon is the most preferred parting agent. The invention extends to a sintering process using the bed and to novel silicon nitride products produced thereby.
Abstract:
Multilayer anti-microbial materials formed to produce an interference colour, and thus an indictor of anti-microbial effect, are provided. The materials include a partly reflective base layer and a partly reflective, partly transmissive top layer balanced to produce an interference colour. The top layer is formed from an anti-microbial metal with atomic disorder. Dissolution or a change in composition of the top layer on contacting an alcohol or electrolyte causes a change in optical path length so as to produce a change in the interference colour of the material. Multilayer, laminated wound dressings are also provided. The dressing includes a first and second layer, and preferably a third layer. The first and third layers are formed of perforated, non-adherent materials and most preferably carry an anti-microbial coating as above. The second layer is sandwiched between the first and third layers and is formed of an absorbent material. At least one of the layers is formed from a plastic material. The layers are laminated together by ultrasonic welds spaced intermittently on the dressing to allow the dressing to be cut to size with delaminating.
Abstract:
An improved dielectric layer of an electroluminescent laminate, and method of preparation are provided. The dielectric layer is formed as a thick layer from a ceramic material to provide: a dielectric strength greater than about 1.0 x 106 V/m; a dielectric constant such that the ratio of the dielectric constant of the dielectric material to that of the phosphor layer is greater than about 50:1; a thickness such that the ratio of the thickness of the dielectric layer to that of the phosphor layer is in the range of about 20:1 to 500:1; and a surface adjacent the phosphor layer which is compatible with the phosphor layer and sufficiently smooth that the phosphor layer illuminates generally uniformly at a given excitation voltage. The invention also provides for electrical connection of an electroluminescent laminate to voltage driving circuitry with through hole technology. The invention also extends to laser scribing the transparent conductor lines of an electroluminescent laminate.