A variety of possible configurations have been developed to exploit the capabilities of the dielectric elastomers. Circular
dielectric actuator is a simple flexible structure that can be used in many areas, for example, it can be employed to adjust
the properties of the optical elements. The configurations of circular dielectric actuators range from one active
dielectric region to multiple active dielectric regions. When the active dielectric regions subjected to a voltage, they will
expand and compress the electrode-less regions. The circular actuator in this work consists of two electrode regions and
two electrode-less regions. One electrode-less region is an annular elastomer sandwiched between the inner dielectric
circle and the middle dielectric annulus. The other electrode-less region is between the middle dielectric annulus and the
rigid frame. We study the properties of the actuator based on the ideal dielectric model and obtain the relationship
between the applied voltage and the deformation. Additionally, the inhomogeneous deformation of the circular actuator
has been investigated both theoretically and experimentally and a good correlation is achieved. The strategy presented
here is generic and can be applied to other circular configurations with multiple regions. The results may contribute to
the use of circular dielectric actuators in advance.
Dielectric elastomer sensors are a recent type of mechanical sensors utilized to detect forces, pressures and deformations.
The sensors have several advantages compared with traditional sensors including high elasticity, capacitive sensing and
inexpensive fabrication. In this paper, a new sensing device for measuring small concentrated force is proposed. The
device deploys the dielectric membrane on the surface of cantilever beam of constant strength. The dielectric membrane
is a capacitance sensor built with dielectric polymer coated with soft electrodes. The change in strain arising from the
cantilever beam with concentrated force at free end can be quickly transferred to the dielectric membrane. The strain
variation of the dielectric membrane induces the change in the capacitance of the membrane. Tests on the device show
that the concentrated force at the free end of the cantilever beam is approximately proportional to the change in the
capacitance. According to the relation, the unknown concentrated force can be obtained accurately by measuring the
change in the capacitance of the dielectric membrane. The new device is capable of monitoring small concentrated force
with prominent sensitivity.