Recent Patents on Mechanical Engineering - Volume 4, Issue 1, 2011

Conducting polymer nanofibers/nanowires especially with an oriented arrangement have attracted great attention because of their unique properties and promising potentiality in nanomaterials and nanodevices, and increasing development for biomedical and biotechnological applications. For example, polyaniline (PANI) is one of the most useful conducting polymers due to its facile preparation, environmental stability, unique doping-dedoping property, and enhanced electrical performance. Herein, combining our recent research work, we have summarized and remarked the approaches developed for fabrication of one dimensional conductive nanofiber/nanowire in the article, mainly focusing on aligned or patterned arrays. The preparation processes have been classified as hard or soft template approach, step-wise electrochemical deposition, wet chemical polymerization, aqueous solution polymerization, interfacial polymerization, and electrospinning synthesis, and the formation mechanism of the polymer nanostructure in each process has been presented in detail. Additionally, some reaction parameters which play a dominant role on the size and shape of the products have been discussed in order to make one know the controlling conditions in that synthesis method. The aligned PANI nanofibers/nanowires, coupled with the useful functionalities of conducting materials, create both aesthetic beauty and scientific attractions. Accordingly, thin film nanofiber sensors can be made of the PANI nanofibers in many patents, having superior performance in both sensitivity and time response to a variety of gas vapors including hydrogen, acids, bases, redox active vapors, alcohols and volatile organic chemicals, as well as decontamination of chemical and biological agents by employing electrospun polymer nanofibers containing metal, metal oxides, metal oxide halogen adducts and mixtures thereof. New exciting applications of the polymer are expected to be discovered and novel synthesizing approaches are envisaged to be devised for the aligned polymer nanostructure based on the present summary

With the energy challenges to come, development of renewable energy sources is becoming more and more topical. But, because these energies are irregularly supplied, their development is closely related to those of suitable energy storage systems. Among the existing technologies for storing thermal energy, latent heat storage appears to be of huge interest since it can lead to reduced size and cost. This paper reviews various recent patents on phase change materials and on latent heat storage systems over the past six years. Developments concerning the storage medium and also the entire storage system are thus addressed. An overview of existing materials and systems for latent heat thermal energy storage, namely for high temperature applications is also given, in order to identify the main issues in the development of such systems. The list of patents reviewed here is by no means supposed to be complete or extensive but shows nevertheless evolution trends concerning latent heat storage. An analysis of the repartition of the reviewed patents helps concluding about the expected future developments in this domain.

Laser Cladding process is one of the most relevant new processes on the industry. Laser Cladding can be applied as rapid manufacturing technique consisting on the direct deposition of metallic alloys layer-by-layer. The resulting parts present a near-net-shape and fully functional properties, which convert this process on a real alternative for the manufacturing of single or very short series of complex geometry parts. On the other hand, Laser Cladding can be applied for coating of previously manufactured parts, in order to obtain optimum surface properties by the addition of a different material. Both applications can be carried out wit the same equipment, which consists basically on a laser source, a kinematic able to transport the laser into a workspace, a material feeder and finally, a headstock that include the optics to focus the laser and the nozzle to inject the added material. The most common industrial solution is to use coaxial powder nozzle to inject the added material into the melt pool. Many of the recent patents and technologies have been focused on the nozzle and powder injection systems in order to increase the powder flow and reduce the diameter of powder stream. This paper presents a study of the main patents focused on Laser Cladding nozzles. The patents have been analyzed and classified into two groups: first, patents developed to describe improvements on nozzles and Laser Cladding systems and, second, patents that purpose new processes, applications or methods for Laser Cladding operations. The analysis shows that, although there are many patented systems and components, there are no closed solutions for industrial Laser Cladding operations.

This paper deals with a Probabilistic Transformation Method (PTM) for structures that require Finite Element Analysis to evaluate their response. The Probabilistic Transformation Method (PTM) is an efficient reliability method to solve problems of mechanical systems with uncertain parameters. This method is readily applicable in the case where the expression between input and output of structures are available in explicit analytical form. However, the situation is much more involved when it is necessary to perform the evaluation of implicit expression between input and output of structures through numerical models. In this paper, we propose technique that combines Finite Element Analysis (FEA), and Probabilistic Transformation Method (PTM) to evaluate the Probability Density Function (PDF) of response where the expression between input and output of the considered structure is implicit. This technique is based on the numerical simulations of the Finite Element Analysis (FEA) and the Probabilistic Transformation Method (PTM) by making an interface between the software ANSYS and Matlab. Some problems of structures are treated in order to demonstrate the applicability of the proposed technique.

Production of small and geometrically complex parts is a typical application of powder injection molding (PIM) process. The production of parts by PIM can produce a final texture with high roughness. The roughness is an important factor of the adhesion of the human cell on the implant. This intrinsic factor can facilitate high bone - implant fixation, but it reduces the corrosion resistance of implants. A design of a temporary screw probe adapted to peculiarities of this production process was proposed to use in implants as well as in electrochemical essays. This study aims at studying the effect of surface roughness on bone attachment of titanium implants and their corrosion resistance in a saline environment. Temporary implants were produced by PIM to characterize the influence of the temperature of sintering on the self-release process of the samples. The samples were classified into three groups according to sintering temperature (1250, 1270 and 1300°C). Screws were inserted in tibiae of New Zealand white rabbits (Oryctolagus cuniculus). After 4, 8 and 12 weeks the fixation in the bone was evaluated by histomorphometry (all threads along the implant and the three best consecutive threads were analyzed). An average surface recovery of 65 % after 12 weeks of implantation was obtained. Accelerated corrosion tests point to possible susceptibility to crevice corrosion of the sintered implants. Here, we compared some of the recent patents related to corrosion behavior and biocompatibility of titanium screws produced by PIM.

This paper presents the most recent and important research trends on the friction and wear properties of diamond like carbon (DLC) coatings deposited on different types of materials. For this the invention, methods, techniques, and design related to this area are discussed. The different trends of tribological properties of materials under different operating conditions are observed. In this article, an attempt is made to provide an opportunity for the future researchers to identify the recent trend of these areas. It is expected that the applications of these results will contribute to the improvement of different concerned mechanical processes. This review article also includes some patents relevant to the method of producing a DLC film.

The patents annotated in this section have been selected from various patent databases. These recent patents are relevant to the articles published in this journal issue, categorized by different analytical methods, designs, manufacturing and analysis of automobiles, aircrafts, manufacturing plants, industrial instruments, machines, heating and cooling systems and processes involved and related to mechanical engineering.