Page 272 - Mechanics of Microelectromechanical Systems

4. Microtransduction: actuation and sensing 259
Problem 4.9
Find the net effect on a loop having the geometry shown in Fig. 4.61
(where R = l/2) and carrying a current I when subject to an external field B.

Figure 4.61 Loop carrying a current in a magnetic field

Answer:
Rotation of the loop about an in-plane direction perpendicular on B and
passing through the semi-circle center; total moment

Problem 4.10
Find the deflection at the midpoint of the microbridge shown in Fig. 4.62,
which is produced by the interaction between the fields of a permanent
magnet attached to the microbridge and the fixed coil carrying a current
The microcantilever cross-section is defined by a width w and a thickness t.

Figure 4.62 Magnetic-electromagnetic interaction via flexible microbridge

Answer:

Problem 4.11
A microcantilever is magnetized as indicated in Fig. 4.39 (c). Determine
the actuation effects at the free end when the external filed is defined by the
law: and the magnetic field source is located underneath the free