Electro-lattice actuator: a compliant high-contractile active lattice structure

Abstract

Electro-ribbon actuators are high-performance electrically-driven artificial muscles with high flexibility, low mass, low power consumption, high contraction, and high force-to-weight ratio. They show great promise for driving the deployment of compact folding structures. This article presents the electro-lattice actuator (ELA), a compliant, three-dimensional, free-standing lattice structure that uses this phenomenon to contract to a flat sheet upon the application of a potential difference. The ELA was designed in the form of multiple interconnected buckled structures and fabricated using polyvinyl chloride sheets and tape and copper electrodes. The ELA structure was pre-set into an open-cell configuration by annealing in an oven. Isometric testing at varying compressions showed that the tensile stress of the proposed lattice actuator reaches a maximum of 184 Pa (a 472 Pa change in tensile stress compared with its unactuated state). A cuboid shaped ELA (13.6 cm length × 10.0 cm width × 5.4 cm height) achieved a contraction of 92.6% and a contraction rate of 35.6% s−1. The novel ELA opens up the use of electro-ribbon actuation to more complex and more effective 3D actuating and deploying structures.

A Magnetically-Actuated Coiling Soft Robot With Variable Stiffness

“…This, however, is non-trivial and one of the significant challenges to the conceptual development of this design. Potential solutions lie in the areas of fluidic actuation [40], phase changing materials [20], electro-statics [41], magnetorheological fluid [21] and vacuum locking [42] and we intend to explore those options with sufficient potential for miniaturization. Further to this we must also develop a mobile mounting system, such as a manual endoscope, to operate.…”

Electrostatic-driven soft air pump with segmented electrodes

“…Electro-pneumatic pump (EPP) pumps were the pioneers in electrostatic actuation among soft air pumps [12]. Prior to this, the electrostatic actuation was commonly utilized in hydraulically amplified self-healing electrostatic (HASEL) actuators [36][37][38][39] and electro-ribbon actuators [40,41] for their benefits of high efficiency, rapid response and low power consumption. The essential principle of EPP involves folding a V-shaped air cavity with flexible electrodes attached to its two air-cavity sides and applying high voltage.…”

Active stiffness tuning of lattice metamaterials

“…Lumpe and Shea [10] utilized multi-material 3D printing method to fabricate active lattice structures that are capable of reversible shape morphing when exposed to heat and can be exploited as an airfoil. Hoh et al [11] designed a 3D electro-lattice actuator that, when actuated by an electrical current, can transform into a thin sheet. The spring-like characteristics of the suggested actuator render it well-suited for implementation in modules that require variable stiffness.…”