Silica microfibers created by roller electrospinning are mechanically tested by performing tensile tests. Both the sample preparation process and the tensile testing are performed using the FT-MTA03 Micromechanical Testing and Assembly Station. First, an individual fiber is collected using a FT-G103 Force Sensing Microgripper and attached on one side onto a glass slide using UV curable glue. Subsequently, the opposite side of the fiber is glued to the probe tip of a FT-S20’000 Microforce Sensing Probe. Using the "tensile testing" function of the FemtoTools Software Suite, the fiber is stretched until it is straight and then stretched even 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.
The quantitative knowledge of the mechanical properties of plants cells is crucial for an accurate understanding of plant growth. In this application the FT-MTA03 Micromechanical Testing And Assembly System 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. For tensile testing, the root hair is stretched while the applied force and the deformation is recorded. From the resulting force-versus-deformation plot it can be observed 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.