In this article, a facile static breath-figure (BF) method to prepare highly ordered polystyrene (PS) thin films was reported. The static process was robust and tolerated more variability in casting conditions, although non-polar linear PS was not believed to be a good candidate for the BF technique. In the following UV irradiation, not only were the microporous structures well preserved, but also thermal and chemical resistance of the films was significantly improved due to the cross-linkage. Moreover, the surface wettability was changed from hydrophobicity to hydrophilicity. The cross-linked honeycomb structured PS films became resistant to a wide range of organic solvents and thermally stable up to 250 C, an increase of more than 150 K as compared to the uncross-linked films. The simple cross-linking operation opened the door to facilely fabricate robust and low-cost microporous polymer films.

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A large-deflection elasticity model was used to describe the mechanical behavior of cartilaginous tissues during three-point bending tests. Force-deflection curves were measured for 20-mm long x 4-mm wide x approximately 1-mm thick strips of porcine auricular and costal cartilage. Using a least-squares method with elastic modulus in bending as the only adjustable parameter, data were fit to a model based on the von Karman theory for large deflection of plates. This model described the data well, with an average RMS error of 14.8% and an average R(2) value of 0.98. Using this method, the bending modulus of auricular cartilage (4.6 MPa) was found to be statistically lower (p < 0.05) than that of costal cartilage (7.1 MPa). Material features of the cartilage samples influenced the mechanical behavior, including the orientation of the perichondrium in auricular cartilage. These methods also were used to determine the elastic moduli of engineered cartilage samples produced by seeding chondrocytes into fibrin glue. The modulus of tissue-engineered constructs increased statistically with time (p < 0.05), but still were statistically lower than the moduli of the native tissue samples (p > 0.05), reaching only about a third of the values of native samples.

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