Page 234 - Mechanics of Microelectromechanical Systems

4. Microtransduction: actuation and sensing 221
reduce the initial gap by half. It is assumed the microsystem is operating in
air and that the circular loop has one coil only.

Solution:
It can be shown that the force which needs to be applied at a distance
measured from the free end in order to produce a deflection of at the free
end of the microcantilever of length l is:

This force is produced by the magnet-coil interaction, and, as a consequence
is also given in Eq. (4.87). By equating Eqs. (4.87) and (4.88), the following
equation is obtained for the current

The reluctance of the system is in this case:

Figure 4.39 Magnetized microcantilever in electromagnetic field: (a) m is parallel to B; (b)
m directed parallel to the microcantilever length; (c) m is perpendicular to the microcantilever
length; (d) m has an arbitrary direction in the microcantilever plane

Another possibility of combining magnetic and electromagnetic fields is
to utilize thin microcantilevers of different magnetizations in order to realize