The current study focuses on improving the wear resistance of femoral head component and enhancing the osseo-integration properties of femoral stem component of a hip implant made of a new generation low modulus alloy, Ti-35Nb-7Zr-5Ta or TNZT. Different techniques that were adopted to improve the wear resistance of low-modulus TNZT alloy included; (a) fabrication of graded TNZT-xB (x= 0, 1, 2 wt%) samples using LENS, (b) oxidation, and (c) LASER nitriding of TNZT. TNZT-1B and TNZT-O samples have shown improved wear resistance when tested against UHMWPE ball in SBF medium. A new class of bio-ceramic coatings based on calcium phosphate (CaP), was applied on the TNZT sample surface and was further laser processed with the objective of enhancing their osseo-integration properties. With optimized LASER parameters, TNZT-CaP samples have shown improved corrosion resistance, surface wettability and cellular response when compared to the base TNZT sample.

Geckos can freely climb on walls and ceilings against their body weight at speed of over 1ms-1. Switching between attachment and detachment seem simple and easy for geckos, without considering the surface to be dry or wet, smooth or rough, dirty or clean. In addition, gecko can shed dirt particles during use, keeping the adhesive pads clean. Mimicking this biological system can lead to a new class of dry adhesives for various applications. However, gecko’s unique dry self-cleaning mechanism remains unknown, which impedes the development of self-cleaning dry adhesives. In this dissertation we provide new evidence and self-cleaning mechanism to explain how gecko shed particles and keep its sticky feet clean. First we studied the dynamic enhancement observed between micro-sized particles and substrate under dry and wet conditions. The adhesion force of soft (polystyrene) and hard (SiO2 and Al2O3) micro-particles on soft (polystyrene) and hard (fused silica and sapphire) substrates was measured using an atomic force microscope (AFM) with retraction (z-piezo) speed ranging over 4 orders of magnitude. The adhesion is strongly enhanced by the dynamic effect. When the retraction speeds varies from 0.02 µm/s to 156 µm/s, the adhesion force increases by 10% ~ 50% in dry nitrogen while …