Development Of Dual-frequency Loading Device And Finite Element Simulation

With the further research of biomechanics in recent years, a new research field"mechanobiology"was gradually formed. It focuses on the mechanical regulation to the biological form and structure of tissue, in other words, it inclines to study how these tissues are maintained and adapted by cells as an response to mechanical stimuli in their environment. Research in this area can make for revealing the mechanism of tissue mechanical conduction, as well as lay the foundation for the development of tissue engineering. Appropriate mechanical environment is an important basis of the bone and cartilage mechanobiology study and the tissue engineering construction.A dual-frequency loading device for the bone mechanobiology study, which based on mechanical characteristics of human activities, has been developed according to tissue engineering and the basic principles of bionic, for the purpose of seeking and building appropriate mechanical environment, The device simulated both the low-frequency high-amplitude loading on articular cartilage as walking or other activities and the high-frequency low-amplitude loading from muscles, ligaments and other tissue in order to maintain the human framework structure. The device can achieve a dual-frequency mechanical environment similar to physiological condition in vivo by controlling adjustable cam and regulating amplitude and frequency of the piezoelectric ceramic. The output displacement of dual-frequency loading device is tested by miniature plane-mirror interferometers. The test results showed that the device operated stability, and could achieve the mechanical environment of low-frequency high-amplitude loading superimposed high-frequency low-amplitude loading; In the dual-frequency loading condition, furthermore, the mechanical responses of cartilage layers differently by usage of finite element method for mechanical analysis of cartilage. When high-frequency of 10Hz and 20Hz superpositioning low-frequency of 1Hz and 2Hz, the cartilage showed different mechanical responses. Cartilage response arisen by 20Hz is stronger than that arisen by 10Hz, but there is little difference between them; Finally, the dual-frequency loading condition is evaluated by biological experiment, the test results showed that the construction of the dynamic mechanical environment enhanced the bio-mass transfer process of cartilage.Mechanical load of the device, which may contribute to the research of tissue mechanical conduction mechanism and the development of tissue engineering, can provide a new mechanical environment for cartilage mechanobiology study of bone.