New Resonance Mode of Dielectric Elastomer Minimum Energy Structure
The dielectric elastomer minimum energy structure (DEMES) can realize large angular deformations by a small voltage-induced strain of the dielectric elastomer, so it is a suitable candidate to make a rotary joint for a soft robot. Driven with an alternating electric field, the joint deformation vibrational frequency follows the input voltage frequency. However, the authors find that if the rotational angel over a negative angle during dynamic response, the resonance mode will be different from the traditional, the vibration with the largest amplitude does not occur while the voltage frequency is equal to natural response frequency of the joint. Rather, the vibrational amplitude will be quite large over a range of other frequencies, at which the voltage frequency is greater than one time of the nature frequency and smaller than two times. This phenomenon was analyzed by relationship between the bending angle, applied voltage and bending moment of the film to the frame on a timeline. This new resonance mode can be applied to some biomimetic soft robots that consist of DEMES rotary joint.
J. W. Zhao et al., "New Resonance Mode of Dielectric Elastomer Minimum Energy Structure", Advances in Science and Technology, Vol. 97, pp. 48-56, 2017