Optics11 CHIARO NANOINDENTER, Руководство пользователя, Страница: 39 / 65

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Figure 31: Simplified optical scheme of the Piuma Nanoindenter.
The two back-propagated waves interfere with each other, of which the resulting intensity is
detected by the photodiode. Whenever a phase shift between the two reflecting interfaces occurs,
the resulting interference will also change, resulting in a higher or lower total intensity at the end of
the photodetector. For a continuous phase shift of these two interfaces, a sinusoidal intensity
pattern at the end of the photodetector can be observed.
The Piuma optical indentation probes
The optical probes used in the Piuma Nanoindenter are manufactured in Amsterdam, and consist of
an optical connector, an optical fiber, a probe holder and an indentation probe, all in one piece.
The cantilever stiffness and tip size of the probe is calibrated at Optics11 and the values are
provided on the probe’s container.
Since the optical probe, the cantilever, and the tip consist of
glass with resistant glue interfaces, the whole probe can be
immersed in any solution that does not affect glass or HT-
epoxy. Often applications involve salt solutions in which a
sample, such as a cell seeded scaffold, is immersed and needs
to be characterized in that state. The Piuma is able to perform
this experiment, as the whole probe can be submersed,
eliminating the need to compensate for surface tension or
medium interface effects. In addition, this enables cleaning the
probe with demi-water or solvents, such as iso-propyl alcohol
or ethanol, to sterilize and re-use the probes.
Figure 32: Side view of Piuma probe.