Investigation on compressive devices based on dielectric elastomer actuators

Dielectric elastomer actuators (DEAs) are an emerging technology from the larger class of artificial muscle actuators, showing interesting properties such as softness and large actuation strains. A DEA can be used to create various types of motions (such as planar, rotary, and bending) and contact forces (such as tension, biaxial compression, and bending moment). Due to its interesting properties, there are a growing number of studies on improving DEA applicability, reliability, and characteristics. Additionally, despite limited commercial use, there is a growing global push toward commercializing DEA in various sectors. In this thesis, in an effort to investigate practical applications of DEAs, their functionality is studied in applications where compressive forces are exerted by the actuator. Two different modalities in which DEAs could apply compressive forces to an encompassed object are identified. To narrow the focus of the thesis, a practical application is introduced and investigated for each modality. The first practical application, based on the first modality, introduces the use of DEAs as a compression bandage to improve blood circulation in the human leg. The proposed compression bandage could potentially enable a controlled variable compression around the lower leg. The second practical application, based on the second modality, proposes a novel gripper that uses DEAs as a mean to apply a soft touch on objects. The proposed gripper can apply up to 2N of grasping force to select objects. The gripper may be adopted as an end effectors for collaborative robotic arms, where a human operator is collaborating with the robotic arm to handle a delicate object. Typically, DEAs are actuated using high electrical voltages of several kilovolts. This operating voltage gives rise to a safety concern for practical applications where DEAs are sought to be operated in proximity to the human body. Since the two aforementioned applications require, or may require the operation of DEAs close to the human body, it is very important to study the electrical safety of DEAs and investigate methods to manage the risk of their high operating voltages. The last part of this thesis discusses the electrical safety of DEAs in scenarios where DEA circuitry is in contact with the human body, and shows that they can be safely used. Critical parameters for identification of the electrical safety of DEAs are also introduced to assist in designing safer DEAs for such applications.