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In order to improve the mechanical properties of HA/PEEK composite, the surface modification of nanosized hydroxyapatite (n-HA) was carried out with silane coupling agent (SCA).The modified particles were produced using different contents of SCA (KH560) and characterized by virtue of Fourier Transform Infrared (FT-IR) spectroscopy. The polyetheretherketone (PEEK) nanocomposite materials reinforced by surface-modified n-HA were successfully prepared and their microstructure and mechanical properties were examined by scanning electron microscopy (SEM), Instron IX Material Testing System and Vickers micro-hardness tester. The result of FT-IR indicated that the nanosized HA was coupled with the SCA by a chemical bonding. SEM observation showed that SCA-HA was well-dispersed in PEEK matrix. The results incicated that mechanical strength of SCA-HA/PEEK composite was improved and best at 5 vol.% HA, 3wt.% SCA.Keywords: nanosized hydroxyapatite; Silane couping agent; Polyetheretherketone; Biocomposite; Mechanical propertity

In order to evaluate the cytocompatibility and hemolytic properties of n-HA/PEEK biocomposites the nanohydroxyapatite/polyetheretherketone (n-HA/PEEK) biocomposites were successfully prepared. The mechanical properties of the biocomposites were proximal to human bone, at the same time, they had the optimal value with the HA volume content of 5%. The PEEK and n-HA/PEEK biocomposites with different HA content extraction medium was prepared with fresh medium. Simple DMEM culture solution was taken as negative control group. The pure PEEK and 5vol.%, 15vol.%, 30vol.% n-HA/PEEK biocomposites were the testing group. The relative proliferation rate of L929 cells was determined on the 1st, 2nd, 3rd and 6th days with CCK-8 assay. The cytotoxicity of n-HA/PEEK biocomposites were evaluated according to ISO 10993-5: 2009. The L929 cells morphology and growth on the 1st, 2nd, 3rd and 6th days were determined under inverted microscope. The hemolysis test in vitro of n-HA/PEEK biocomposites were evaluated through measuring erythrocyte lysis and ferro-hemoglobin freeing degree with indirect contact method basing on ISO 10993-4:2009. The experimental results showed that the growth and morphology of cells in pure PEEK and n-HA/PEEK biocomposites extraction medium had no difference from negative control group. Cytotoxicity test showed that PEEK and n-HA/PEEK biocomposites did not have obvious toxicity on L929 cells, and the cytotoxicity of these extracts was in grade 0-1. Hemolysis test suggested that PEEK and n-HA/PEEK biocomposites did not have obvious hemolysis reaction, and the hemolysis rate of PEEK and n-HA/PEEK biocomposites were 2.37%, 1.71%, 1.05% and 1.32% respectively, which are less than the national standard (5%). It may be concluded that the n-HA/PEEK biocomposites did not have obvious cytotoxicity and hemolysis reaction, which demonstrated that n-HA/PEEK biocomposites had good cytocompatibility.

Based on the kinematic model with Cartesian structure, Newton-Euler like algo¬rithm being employed to solve the nonlinear equations of motion and constraints in real-time application, and dynamic multibody simulation, a novel integrated design for a 6-DOF ro¬bot is investigated, and the interfaces required for the implementation of different computer aided engineering (CAE) tools used in the design is addressed [1].The presented method in this paper was analyzed and verified by the numerical and physical 6-DOF robot model, the result shows that the topologic projection me-thod [2] is stable. The design experience accumulated will be very useful for the future product de-sign.