With increasing gap in the demand and supply of vital organs for transplantation there is a pressing need to bridge the gap with substitutes. One way to make substitutes is by tissue engineering which involves combining several types of synthetic or biomaterials, cells and growth factors cross-linked together to synthesize a functional scaffold for repair or replacement of non-functional organs. Nanoparticle based composites are gaining importance in tissue engineering due to their ability to enhance cell attachment and proliferation. The current study focuses on synthesizing agarose composites embedded with chitosan-coated silver nanoparticles using glutaraldehyde as the cross-linker. The synthesis of chitosan coated silver nanoparticles within the scaffold was confirmed with UV-visible spectroscopy. Physical and chemical characterization of the synthesized nanoparticles were done by XRD, FTIR, TGA and SEM. DMA showed higher mechanical strength of the scaffolds. The scaffolds showed degradation of ∼37% within a span of four weeks. The higher physical support provided by the synthesized scaffolds was shown by in-vitro cell viability assay. Broad spectrum anti-bacterial activity and superior hemocompatibility further showed the advantage it offered for growing cells. Thus a biopolymer based nanocomposite was synthesized, with intended widespread use as scaffold for engineering of soft tissues due to its enhanced biocompatibility and greater surface area for cell growth.

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LM6 was reinforced with various percentages of ZrO2 particles by using stir casting method. The prepared samples were subjected to tensile and wear test at variable loads by using a pin-on-disc wear tester. The curve fitting technique was used to develop the respective linear, logarithmic, polynomial, power law equations. The wear worn surface and surface roughness of the specimen were studied. Response Surface Methodology (RSM) was used to minimize the number of experimental conditions and develop the mathematical model between the key process parameters namely weight percentage of ZrO2, load and sliding distance. Analysis of Variance technique was applied to check the validity of the developed model. The mathematical model developed for the specific wear rate was predicted at 99% confidence level and some useful conclusions were made.

The effect of microstructural refinement and presence of TiB particles on the electrical discharge machinability of hypoeutectic B-modified Ti-6Al-4V alloys have been studied. This has been characterized on the basis of changes in the following machining responses: material removal rate and tool wear rate. Material removal rate remains unaffected by B addition to Ti-6Al-4V because of insignificant changes in hardness and melting point of the alloy with B modification. On the other hand, microstructural refinement associated with minor amount of B addition leads to enhancement in alloy strength, and hence, tool wear rate has been found to reduce constantly with increasing the amount of B addition. Moreover, the shielding effect of TiB particles, which have higher melting temperature and hardness compared to the Ti-6Al-4V matrix, has also been found to control the wear of the tool.

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Machining of microchannels (µ-channels) on hard conducting materials can be performed effectively using a micro electric discharge milling (µED-milling) process. The method of bulk machining is considered in this work, as it takes less machining time than conventional layer-by-layer machining. However, the tool wear in this method occurs both in the side and bottom of the tool, which causes dimensional inaccuracy. Hence, to achieve the desired µ-channel shape, the technique of multiple-pass machining is introduced, wherein a dressed tool is used in each pass to compensate tool wear. The basic idea behind the work is to compute the number of passes and machining time required in achieving the shape. A computer-aided design-based algorithm is used to simulate the shape of the µ-channel and tool for a single pass and for further multiple passes. At the end of each pass, the volume of material removal and tool wear are estimated quantitatively. The desired channel shape is considered to be achieved when the volume of the material left-out is less than or equal to 5 per cent of the ideal volume to be removed. This paper elaborates on the procedure for single- and multiple-pass simulation to determine the number of passes and machining time. The results are validated with experiments for the desired µ-channel shape.

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