Microfibers are a promising material for composite materials, filters, scaffolds (tissue engineering), drug delivery, wound dressings and textiles. Therefore, the quantitative knowledge of the mechanical behavior (stiffness, elastic deformation range, ultimate strength, toughness, etc.) of microfibers is critical to understand their performance in the target application.
Application Example: Microscale Tensile Testing of Silica Fibers
Silica microfibers are mechanically tested by tensile testing. Both the sample preparation process and the tensile testing are performed using the FT-MTA03 Micromechanical Testing and Assembly System. Using the "tensile testing" function of the FemtoTools Software Suite, the fiber is pulled on until it is straight and then stretched further. The stiffness, the elongation, the maximum yield strength and the maximum elongation are measured. The relaxation behavior is analyzed by stretching the fiber and measuring the force while keeping the position constant. Cyclic testing is performed to measure the change of stiffness and fiber elongation after a large number of loading and unloading cycles.
Application Example: Microscale Testing of Root Hairs
In this application the FT-MTA03 is used for the tensile testing and fracture testing of a single root hairs. For this purpose the tungsten tip of the FT-S Microforce Sensing Probe is glued to the end of the root hair. During the tensile test, the root hair is stretched while the applied force and the deformation is recorded. The resulting force-versus-deformation plot, shows that after an initial loading, the root hair starts to fracture, as indicated by a force drop. However, the root hair does not fail completely but rather only fractures partially and starts to form a helical shape. As the force is increased, the root hair continues to form more fractures while completely transforming into a helix.