Submicron bioactive glass fibers 70S30C (70 mol% SiO(2), 30 mol% CaO) acting as bone tissue scaffolds were fabricated by electrospinning method. The scaffold is a hierarchical pore network that consists of interconnected fibers with macropores and mesopores. The structure, morphological characterization and mechanical properties of the submicron bioactive glass fibers were studied by XRD, EDS, FIIR, SEM, N(2) gas absorption analyses and nanoindentation. The effect of the voltage on the morphology of electrospun bioactive glass fibers was investigated. It was found that decreasing the applied voltage from 19 to 7 kV can facilitate the formation of finer fibers with fewer bead defects. The hardness and Young's modulus of submicron bioactive glass fibers were measured as 0.21 and 5.5 GPa, respectively. Comparing with other bone tissue scaffolds measured by nanoindentation, the elastic modulus of the present scaffold was relatively high and close to the bone.

A tetragonal polyvinyl alcohol (PVA) scaffold with 3D orthogonal periodic porous architecture was fabricated via selective laser sintering (SLS) technology. The scaffold was fabricated under the laser power of 8 W, scan speed of 600 mm min(-1), laser spot diameter of 0.8 mm and layer thickness of 0.15 mm. The microstructure analysis showed that the degree of crystallization decreased while the PVA powder melts gradually and fuses together completely with laser power increasing. Thermal decomposition would occur if the laser power was further higher (16 W or higher in the case). The porous architecture was controllable and totally interconnected. The porosity of the fabricated scaffolds was measured to be 67.9 ± 2.7% which satisfies the requirement of micro-pores of the bone scaffolds. Its bioactivity and biocompatibility were also evaluated in vitro as tissue engineering (TE) scaffolds. In vitro adhesion assay showed that the amount of pores increased while the scaffold remains stable and intact after immersion in simulated body fluid for seven days. Moreover, the number of MG-63 cells and the bridge between cells increased with increasing time in cell culture. The present work demonstrates that PVA scaffolds with well-defined porous architectures via SLS technology were designed and fabricated for bone TE.

Thermoplastic composite filament winding is a viable technique for manufacturing composite-reinforced pressure pipes and vessels. Residual stresses developed during the filament winding process have already received much attention in the past. Unreasonable residual stresses may result in distortion, matrix cracking, and interply delaminations. A model containing four submodels is developed in a previous research work. Some methods, such as adjusting tape tensions and temperatures are found to control the residual stress profile. The residual stress profile can be adjusted to a satisfactory level, which can avoid defects and even reduce weight and save material. Adjusting the tape tension is one of the parameters that controls the residual stress in thermoplastic composite filament winding. From a practical point of view, it is easy to realize even on an industrial scale. Experiments on two materials (glass fiber–polypropylene (G–PP) and carbon fiber–poly(ether-ether-ketone) (C–PEEK)) are made by using a variety of different tape tensions. The results proved the conclusions of theoretical work and agree well with the model predictions.

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