Page 140 - Mechanics of Microelectromechanical Systems
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2. Microcantilevers, microhinges, microbridges 127
The maximum tip slopes are determined experimentally as:
and
Answer:
The corresponding numerical values are: and
Problem 2.5
In a microcantilever-based force detection application the experimental
equipment can sense maximum tip displacements of and
A rectangular design can be used in a rectangular envelope of
and The microfabrication technology produces a thickness of
and the tip has a height of The material is polysilicon with E =
130 GPa. What are the forces and that can be detected by a solid
configuration and by a hollow one (both designs have the same square cross-
section) ?
Answer:
For the solid design the forces are: and
For the hollow configuration they are: and
Problem 2.6
A hollow microcantilever needs to be designed in either a triangular or a
rectangular configuration in an application where the direct linear
compliance about the sensitive bending axis has to be maximum. If the cross-
section is a square with the side and the geometrical envelope for
both design variants is a rectangle of length and width
decide the design that has to be selected.
Answer:
For the triangular design the main geometric parameters are:
The triangular-to-rectangular compliance ratio is 1.034, and therefore the
triangular design should be utilized in this application.
