Herein, a flexible piezoelectric nanogenerator composed of electrospun talc/PVDF [poly(vinylidene fluoride)] nanocomposite fabrics has been developed. These nanocomposite fabrics demonstrated enhanced mechanical and piezoelectric properties compared with pristine PVDF nanofabrics. In particular, nanocomposite fabrics with 0.50 wt% talc yielded 89.6% of polar β-phase in the PVDF matrix, thereby augmenting its piezoelectric response. X-ray diffraction, Fourier transform infrared spectroscopy, and differential scanning calorimetry conclusively affirmed the promotion of polar β-phase in the talc/PVDF nanocomposite fabrics. The 0.50 wt% talc/PVDF nanocomposite fabric based nanogenerator produced an open-circuit voltage and power density of 9.1 V and 1.12 μW cm⁻², respectively, under repetitive finger tapping mode (under a load of 3.8 N). Furthermore, the nanogenerator was also subjected to frequency modulated-shaker mode, wherein an output voltage of 8.9 V was produced. Improved flexibility, mechanical robustness, and enhanced piezoelectric responsiveness of this nanogenerator could possibly pave the way for its use in portable self-powered devices.

Background/Objectives: The increasing demand for total hip arthroplasty (THA), due to aging populations and active lifestyles, necessitates advancements in implant materials and design. This review evaluates the role of surface coatings in enhancing the performance, biocompatibility, and longevity of hip implants. It addresses challenges like wear, corrosion, and infection, focusing on innovative surface engineering solutions. Methods: The review analyzes various surface modification techniques, including physical vapor deposition (PVD), chemical vapor deposition (CVD), electrophoretic deposition (EPD), plasma spraying, and ion implantation. It also examines their effectiveness in improving tribological properties, biocompatibility, and resistance to infection. Computational methods such as finite element analysis (FEA) are discussed for predicting potential coating failures. Results: The findings underscore the challenges posed by wear debris and corrosion in common configurations, like metal-on-metal (MoM) and metal-on-polyethylene (MoP). Innovative coatings, such as diamond-like carbon (DLC) films and hydroxyapatite (HA) layers, demonstrate enhanced performance by reducing friction, wear, and bacterial adhesion, while promoting osteogenic cell attachment. Surface textures and optimized tribological properties further improve implant functionality. Multifunctional coatings exhibit potential in balancing biocompatibility and infection resistance. Conclusions: Surface engineering plays a critical role in advancing next-generation hip implants. The integration of advanced coatings and surface modifications enhances implant durability, reduces complications, and improves patient outcomes. Future research should focus on combining innovative materials and computational modeling to refine coating strategies for long-term success in THA.

Fatigue failure is one of the causes of the failure of hip implants. The main objective of this work is to carry out fatigue failure analysis on different hip profiles and compare the outcomes for various combinations of materials. Three profiles each for circular, oval, elliptical, and trapezoidal stems are utilized for this study with four different material combinations consisting of materials like Ti-6Al-4V, CoCr Alloy and UHMWPE. CATIA V-6 is used for the modelling of these implants and the fatigue analysis using Goodman's mean stress theory is simulated using ANSYS 2022 R1. ISO 7206-4 and ASTM F2996-13 standards are used to define the boundary conditions. A total of 48 combinations were studied across four different shapes, three different profiles and four different material combinations to deduce the best possible combination for a hip implant for static and fatigue loading. Comparison of the implants is based on the factors like equivalent von Mises stress, displacement, equivalent elastic strain, fatigue life, safety factor and equivalent alternating stress. Profile 2 of the trapezoidal-shaped hip implant with a Ti-6Al-4V stem exhibited superior results both under static and fatigue loading conditions. Compared to displacements obtained for profiles one and three, profile 2 trapezoidal stem with Ti-6Al-4V and other parts as CoCr Alloy has about 72% lower displacement. Based on the findings, profile 2 with a trapezoidal stem made of Ti-6Al-4V and an acetabular cup made of CoCr shows the enhanced results over the other combinations considered.

The growing need for sustainable materials in architecture has sparked significant interest in natural-fiber-based composites. Among these, coconut coir, a by-product of the coconut industry, has emerged as a promising raw material owing to its abundance, renewability, and excellent mechanical properties. The promise of coir-based composites in architecture is highlighted in this review, which also looks at their problems, advantages for the environment, manufacturing processes, and mechanical, thermal, and acoustic performances. The fibrous shape of the coir provides efficient thermal and acoustic insulation, while its high lignin concentration guarantees stiffness, biological resistance, and dimensional stability. Fiber-matrix adhesion and durability have improved owing to advancements in treatment and environmentally friendly binders, opening up the use of cement, polymers, and hybrid composites. In terms of the environment, coir composites promote a biophilic design, reduce embodied carbon, and decrease landfill waste. Moisture sensitivity, inconsistent fiber quality, and production scaling are obstacles; however, advancements in hybridization, grading, and nanotechnology hold promise. This review provides comprehensive, architecture-focused review that integrates material science, fabrication techniques, and real-world architectural applications of coir-based composites. Coir-based composites have the potential to be long-lasting, sustainable substitutes for conventional materials in climate-resilient architectural design if they are further investigated and included in green certification programs and the circular economy.

Patient-specific dynamic loadings are seldom considered during the evaluation of hip implants. The primary objective of this study is to check for the feasibility of the use of UHMWPE as the material for an acetabular cup o CoCr Alloy that is reported to produce a squeaking sound after replacement. An elliptical shaped stem with three different cross-sectional profiles is considered for simulation. Using a commercial finite element method, patient-specific dynamic forces were applied for the quantitative analysis. The loading and boundary conditions are used as per ISO and ASTM standards. The walking gait cycle is used with two widely used biocompatible materials: titanium and cobalt-chromium. Initially, only the stem is considered for the analysis to finalize the best out of the three profiles, along with the better material for the stem. Later the complete implant is used for the analysis. Profile 1 exhibits 1.25 and 1.17 times greater stress than Profile 2 for CoCr Alloy and Ti–6Al–4V, respectively. Similarly, Profile 3 displays stresses 1.26 and 1.25 times greater than Profile 2 for CoCr Alloy and Ti–6Al–4V, respectively. Comparatively, displacement in stem Profile 2 is 1.75 times higher in Ti–6Al–4V than CoCr Alloy. The full implant displacement at 14% gait cycle is 1.15% higher for the CoCr-acetabular column material combination when compared to UHMWPE. It can be concluded that UHMWPE can be used as the acetabular cup material instead of CoCr for the Profile 2 elliptical shaped hip implant to prevent squeaking after replacement.