The mechanical characteristics of solid and flexible structures based on single-walled carbon nanotubes and biopolymers
A method for laser formation of biopolymer structures based on single-wall carbon nanotubes has been developed. The structures were formed layer-by-layer by depositing aqueous layers of dispersions on a substrate, followed by laser irradiation until they were transformed into a solid state. Depending on intensity of pulsed laser irradiation the biopolymer structures were formed in solid or flexible state. It is known, that carbon nanotubes are osteoinducers and can be used as the fillers for bone implants development. The indentation method was used to build hardness distribution maps at different depths of the structure relative to the surface of the dispersion layer. The hardness distribution of structures was obtained from 50 to 300 MPa. Bone hardness of middle-aged man is about 500 MPa. Thus, the constructs can be substitutes for bone tissue defects.
Biopolymer structures in flexible state were subjected to cyclic load (fatigue strength study) to determine the possibility of their use as basis for cardiac implants. It was determined that when structures are stretched, the stresses arising in them are quite close in values to the values of the heart tissue. Based on heart tomography data on different stages of contraction was created an algorithm that made it possible to simulate heart work during 4 months. The tensile strength of structure has decreased ~3 – 4 times compare the tensile strength of original structures without cyclic loads and amounted 1.6 and 6.9 MPa, respectively. The resulting tensile strength of structures were commeasurable with tensile strength of left ventricular myocardium of man at the age from 31 to 40 (2.1-3.1). With increasing age, the tensile strength gradually decreases. Thus, biopolymer structures has sufficient fatigue strength to withstand the incessant stress in contracting heart in the body. This study was supported by the Russian Science Foundation, Project No. 20-49-04404.
National Research University of Electronic Technology MIET
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