A Worm-Like Biomimetic Crawling Robot Based on Cylindrical Dielectric Elastomer Actuators

Abstract

In recent years the field of soft robotics has gained a lot of interest both in academia and industry. In contrast to rigid robots, which are potentially very powerful and precise, soft robots are composed of compliant materials like gels or elastomers (Rich et al., 2018; Majidi, 2019). Their exclusive composition of nearly entirely soft materials offers the potential to extend the use of robotics to fields like healthcare (Burgner-Kahrs et al., 2015; Banerjee et al., 2018) and advance the emerging domain of cooperative human-machine interaction (Asbeck et al., 2014). One material class used frequently in soft robotics as actuators are electroactive polymers (EAPs). Especially dielectric elastomer actuators (DEAs) consisting of a thin elastomer membrane sandwiched between two compliant electrodes offer promising characteristics for actuator drives (Pelrine et al., 2000). Under an applied electric field, the resulting electrostatic pressure leads to a reduction in thickness and an expansion in the free spatial directions. The resulting expansion can reach strain levels of more than 300% (Bar-Cohen, 2004). This paper presents a bioinspired worm-like crawling robot based on DEAs with additional textile reinforcement in its silicone structures. A special focus is set on the developed cylindrical actuator segments that act as linear actuators.

Position and Force Control of a Twisted and Coiled Polymeric Actuator

“…The output is the actual contraction deformation or force of the TCP. G P T is the transfer function described in (2), whose subscript denote the input and output variables. X(T) is the relationship between TCP temperature and strain described in (3), while F(T) is the relationship between TCP temperature and the force response F described in (4).…”

Finite element modeling of electro‐viscoelasticity in fiber reinforced electro‐active polymers

“…Where in some classes of EAP, activation time of less than 1 ms is demonstrated 1,2 and strains up to more than 300% are recorded. 3 Due to those properties, several prototypes of biomimetic actuators and grippers have been based on EAP, [4][5][6][7][8] with fibers embedded either in the EAP itself, or in the passive portion of the structure. For instance, anisotropy is introduced in EAP by aligning fibers in a certain orientation, in order to break the symmetry and to obtain bending deformation of the composite along predefined directions.…”

Thermo-Electro-Mechanical Characterization of PDMS-Based Dielectric Elastomer Actuators

“…Since deformation strains bigger than 100% were reported by Pelrin et al [ 1 ], the number of publications increased rapidly. DEA are used in a wide variety of areas but find their most frequent use in soft robotics and sensor application [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. They are lightweight, their laboratory-scale production is reasonable and their deformation potential is outstanding [ 9 ].…”