Very often, the analysis of microscopic samples requires challenging sample preparation steps due to the small sample size of the objectives being studied. It is possible to equip the FT-MTA03 with the FemtoTools force sensing microgrippers. This allows the force-controlled handling of microscopic objects that are delicate, without damaging their structure.
The sample preparation of a microfiber for micromechanical testing is illustrated by the image sequence. Initially, a single fiber is extracted from a larger fiber bundle and this is followed by dipping the fiber into a droplet of UV curable glue on one end and then attaching the fiber to the border of a glass slide. This method enables the Microforce Sensing Probe to be attached to the other side of the sample for tensile testing.
Microscale Tensile Testing of Silica Fibers
Tensile tests are performed to mechanically characterize silica microfibers developed by roller electrospinning. Both the tensile testing and the sample preparation process are carried out using the FT-MTA03 Micromechanical Testing and Assembly System.
An individual fiber is initially collected using a FT-G103 Force Sensing Microgripper and attached on one side onto a glass slide using UV curable glue. Then, the opposite side of the fiber is fixed to the probe tip of a FT-S20’000 Microforce Sensing Probe.
In the upper microscope image, the fiber is shown in a relaxed state. This fiber is stretched until it is straight and then stretched even further. The maximum elongation, maximum yield strength, elongation, and the stiffness are measured.
In addition, the relaxation behavior is examined by stretching the fiber and measuring the force while maintaining the position constant. Cyclic testing helps to measure the change in stiffness and fiber elongation after several loading and unloading cycles.
Microscale Testing of Root Hairs
Plant growth can be accurately understood by gaining a quantitative knowledge of the mechanical properties of plants cells. Fracture testing and tensile testing of a single root hair is demonstrated in this application. For this purpose, the tungsten tip of the FT-S Microforce Sensing Probe is fixed to the end of the root hair.
To perform tensile testing, the root hair is stretched while the applied force and the deformation is recorded. The resulting force-versus-deformation plot highlights that after an initial loading, the root hair begins to fracture, as indicated by a force drop.
Yet, the root hair does not completely fail but rather only partially fractures and then begins to form a helical shape. When the force is increased, the root hair continuous to form more fractures while fully transforming into a helix.
This information has been sourced, reviewed and adapted from materials provided by FemtoTools AG.
For more information on this source, please visit FemtoTools AG.