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4. Microtransduction: actuation and sensing 249
that needs to be applied at the bimorph’s free end in order to bloc the actuator
is calculated as previously detailed and is:
Example 4.18
Study the relationship between the short patch length and its position
on the microcantilever to the free displacement produced by a bimorph
with dissimilar lengths.
Solution:
For given thicknesses and material properties of the bimorph, the free
displacement expressed in Eq. (4.156) depends on two parameters: the
position of the shorter patch, and its length, It can be shown that the
free displacement is proportional to the function:
Figure 4.56 is a three-dimensional plot of the function defined in Eq. (4.158).
It can be seen that in order to maximize this function, and consequently the
free displacement, the upper layer should be placed towards the root of the
actuator and its length should be as large as possible.
Figure 4.56 Free displacement function plot in terms of length and position of active layer
9 MULTIMORPH TRANSDUCTION
A multimorph is composed of more than two structural layers that are
sandwiched together. Strain can be induced externally in each or just some of
the layers, and the differential axial deformation, which is the result of
