Development And Application Of A Novel Liquid-loading Device For Biomechanical Testing On Skin Tissue

Research of biomechanical testing on skin soft tissue is significant for understanding the physiological function of skin and making correct assessment of skin transplantation and new-type material for replacement. With the booming development of tissue engineering, it is becoming more and more important to quantitatively measure the biomechanical properties of artificial skin. This research designed and developed a novel liquid-loading device for biomechanical testing on skin tissue. The instrument can not only be used for biomechanical testing on ordinary skin tissue by getting the material parameter values for a constitutive law, such as the stress-strain relationship, stress relaxation, creep deformation due to its viscoelastical substance; but it can also be applied for the artificial skin to investigate the stress-strain relationship and ultimate strength as the pressure is gradually applied.The following results were attained:1. The thesis analyzed the current literature and summarized the up-to-date experimental methods on skin biomechanics test.2. This project was the first to propose a new liquid-loading method for biomechanical testing on skin tissue. Based on the nonlinear viscoelasticity of skin and incompressibility of liquid, this method can, with mathematical calculation, successfully describe the skin tissue in three dimensions through the deformation sustained with the volume of loaded liquid. Meanwhile, the device can maintain the sample in a physiological normal environment and keep its biomechanics properties and thus largely improve the confidence in measuring accuracy comparing with the method of gas-loading.3. Design and construction of adjustable pressure fixing equipment for a testing platform. This equipment is composed of twin cylinder which fix skin sample on the clamp by auto control. The fixing pressure can be adjustable according to different kinds of skin samples, which ensures the skin tissue neither to slipper and drop off nor to be damaged.4. Design a system for auto-loading driving and efficient data acquisition based on data acquisition card. It successfully achieved loading and unloading control and pressure values during the deformation process.5. Using this device to do biomechanical testing on the rabbit abdomen skin, suckling mouse skin and artificial skin. As it turned out, the device and measuring system were easy to operate. The stability and repeatability of the measuring results were good. It can meet the requirements of artificial skin testing and experimental research.