Biomedical Engineering Reference
In-Depth Information
5
4
3
2
1
0
0 0 0 0 0 0 0 0 0 0
Deformed angle relative to standing position (degree)
E
, versus displacement. Note
that the displacement is shown in terms of the deformed angle relative to standing position
in degree. The dimension of the sample sensor is 5
FIGURE 7.9
DC sensing data in terms of produced voltages,
∆
×
25
×
0.12 mm.
in terms of the voltage produced at different displacement. Note that the displacement
is shown in terms of the deformed angle relative to standing position in degree. The
dimension of the IPMNC sample sensor is 5
0.12 mm. Such direct mecha-
noelectric effect is convenient in that the produced voltage is large and applicable
displacement is large.
Comparing such unique features of IPMNCs as sensing devices relative to other
current state-of-the-art sensing technologies such as piezoresistive or piezoelectric
devices, one can find more flexibility in connection with IPMNCs.
The slow current leakage due to redistribution of ions is often observable.
Additional investigations of the current leakage are necessary to stabilize the voltage
output of the IPMNCs in a sensing mode.
×
25
×
7.3
EVALUATION OF IPMNCS FOR USE AS NEAR-DC
MECHANICAL SENSORS
7.3.1
I
NTRODUCTION
Henderson and coworkers (2001) and Shahinpoor et al. (2001) offer information on
using IPMNCs as near-DC mechanical sensors. IPMNC active elements enable near-
DC acceleration measurement devices with modest power, volume, mass, and com-
plexity requirements, provided their unique properties are accounted for in the
design. Advantages over conventional piezoelectric elements are documented for
some applications.
Acceleration measurements are necessary for various dynamics experiments and
often serve as sensing inputs in structural control systems. In conventional practice,
a piezoelectric element, as part of a single degree-of-freedom harmonic system, is
