Dielectric elastomer cantilever beam sensor

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.