Enhanced mechanical properties of silicone hydrogels coated with metallic nanoparticles by using the laser-assisted process

Silicone hydrogels coated with metallic nanostructures have attracted extensive attention because of their versatile applications in biomedical devices. However, few studies have been reported for characterizing the mechanical behavior of silicone hydrogel under biaxial tensile stresses. In addition, compared to most chemical coating processes, the deposition of nanostructures on silicone hydrogel by using a laser-assisted process can avoid chemical impurities and additional sterilization processes. Herein, a laser-assisted process is used for producing polyvinylpyrrolidone (PVP) modified silver (Ag) nanoparticles (Ag-PVP NPs), which are further deposited on silicone hydrogel. In the uniaxial mechanical test, the value of Young's modulus of Ag-PVP NP coated silicone hydrogels is increased as compared to that of silicone hydrogel. The energy absorption of silicone hydrogel and Ag-PVP NP coated silicone hydrogel measured by the uniaxial mechanical test is 15.137 ± 0.412 and 22.014 ± 0.186 MJ/m3, respectively. Furthermore, the biaxial test is applied to study the mechanical properties of silicone hydrogel coated with Ag-PVP NPs. Meanwhile, a constitutive model was applied to further understand the mechanical behavior of silicone hydrogel coated with Ag-PVP NPs. The result indicates that silicone hydrogel coated with Ag-PVP NPs shows a pseudo-elastic nonlinear behavior which is similar to collagen-based tissue substitutes.