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Carbon Nanotubes – Interactions with Biological Systems

his book chapter discusses the prospective biomedical applications of carbon nanotubes based materials, the impact of carbon nanotubes properties in the interaction with biological systems. Protein adsorption, impact on cell viability and cytokine production are explored. Potential respiratory and dermal toxicity are reviewed, as the difficulties on studying the biological response. In face of recent studies, s...

Polymeric piezoelectric actuator substrate for osteoblast mechanical stimulation

Abstract Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. A wide variety of devices have been tested for mechanical stimulation of cells and tissues in vitro. The aim of this work was to...

Piezoelectric actuator: searching inspiration in nature for osteoblast stimulation

Abstract Bone is a composite with piezoelectric properties. Bone mass and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels, but the role piezoelectricity plays in bone physiology is yet to be understood. Physical activity enhances bone density, through mechanical stimulation. Osteocytes and osteoblasts are essential for mechanosensing and mechanotransduction. Str...

Piezoelectric bone stimulation: should we move closer to nature?

The aim of this work was to experimentally validate the use of piezoelectric materials as a mean of directly straining bone cells by converse piezoelectric effect.

Tool effects on hybrid laminates drilling

Fibre reinforced plastics are increasing their importance as one of the most interesting groups of material on account of their low weight, high strength and stiffness. To obtain good quality holes, it is important to identify the type of material, ply stacking sequence and fibre orientation. In this paper, the drilling of quasi-isotropic hybrid carbon+glass/epoxy plates is analyzed. Two commercial drills and a...

Experimental and Numerical simulation of mechanical actuators coated with PMMA ...

Bone mass distribution and structure are dependent on mechanical stress and adaptive response at cellular and tissue levels. Mechanical stimulation of bone induces new bone formation in vivo and increases the metabolic activity and gene expression of osteoblasts in culture. The aim of this work was to experimentally validate the possibility of using piezoelectric materials as a mean of stimulating mechanically ...

Damage analysis of carbon/epoxy plates after drilling

Drilling of composites plates normally uses traditional techniques but damage risk is high. NDT use is important. Damage in a carbon/epoxy plate is evaluated by enhanced X-rays. Four different drills are used. The images are analysed using Computational Vision techniques. Surface roughness is compared. Results suggest strategies for delamination reduction.

Comparison of Tool Effects on Hybrid Laminates after Drilling

For the past decades fibre reinforced plastics are increasing their importance as one of the most interesting group of material because of their low weight, high strength and stiffness. Good hole drilling processes are essential. To obtain good quality holes it is important to identify the type of material, ply stacking sequence and fibre orientation. In this paper drilling of quasi-isotropic hybrid carbon+glas...

Avaliação do Dano na Furação de Laminados Carbono/Epóxido

Estudo da Furação de Laminados Carbono/Epóxido com Diferentes Brocas

A furação de placas em materiais compósitos surge da necessidade de efectuar a montagem das peças em estruturas. Embora seja corrente o uso de técnicas tradicionais de furação, estas devem ser devidamente adaptadas de forma a reduzir a geração de danos mecânicos e térmicos. O defeito mais grave é a delaminação, que nem sempre é visível à superfície e pode causar o colapso prematuro das estruturas em serviço. A ...