Modeling and experimental validation of a bi-stable out-of-plane DEAP actuator system

Hodgins, Micah; York, Alexander; Seelecke, Stefan

doi:10.1088/0964-1726/20/9/094012

Cited by 37 publications

(26 citation statements)

References 25 publications

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“…39 They illustrated this using a simple bi-stable over-arm mechanism linking an extension spring with a DE actuator. This was later explored by Hodgins et al 40 in an experimental and modeling study of a system for out-of-plane actuation. A frame that supports the DE membrane can also provide a tunable stiffness for the membrane to work against.…”

Section: Multi-degree-of-freedom De Actuationmentioning

confidence: 99%

Multi-functional dielectric elastomer artificial muscles for soft and smart machines

Anderson

Gisby²,

McKay³

et al. 2012

Journal of Applied Physics

565

314

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Dielectric elastomer (DE) actuators are popularly referred to as artificial muscles because their impressive actuation strain and speed, low density, compliant nature, and silent operation capture many of the desirable physical properties of muscle. Unlike conventional robots and machines, whose mechanisms and drive systems rapidly become very complex as the number of degrees of freedom increases, groups of DE artificial muscles have the potential to generate rich motions combining many translational and rotational degrees of freedom. These artificial muscle systems can mimic the agonist-antagonist approach found in nature, so that active expansion of one artificial muscle is taken up by passive contraction in the other. They can also vary their stiffness. In addition, they have the ability to produce electricity from movement. But departing from the high stiffness paradigm of electromagnetic motors and gearboxes leads to new control challenges, and for soft machines to be truly dexterous like their biological analogues, they need precise control. Humans control their limbs using sensory feedback from strain sensitive cells embedded in muscle. In DE actuators, deformation is inextricably linked to changes in electrical parameters that include capacitance and resistance, so the state of strain can be inferred by sensing these changes, enabling the closed loop control that is critical for a soft machine. But the increased information processing required for a soft machine can impose a substantial burden on a central controller. The natural solution is to distribute control within the mechanism itself. The octopus arm is an example of a soft actuator with a virtually infinite number of degrees of freedom (DOF). The arm utilizes neural ganglia to process sensory data at the local “arm” level and perform complex tasks. Recent advances in soft electronics such as the piezoresistive dielectric elastomer switch (DES) have the potential to be fully integrated with actuators and sensors. With the DE switch, we can produce logic gates, oscillators, and a memory element, the building blocks for a soft computer, thus bringing us closer to emulating smart living structures like the octopus arm. The goal of future research is to develop fully soft machines that exploit smart actuation networks to gain capabilities formerly reserved to nature, and open new vistas in mechanical engineering.

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Section: Multi-degree-of-freedom De Actuationmentioning

confidence: 99%

Multi-functional dielectric elastomer artificial muscles for soft and smart machines

Anderson

Gisby²,

McKay³

et al. 2012

Journal of Applied Physics

565

314

View full text Add to dashboard Cite

show abstract

“…The design that we propose is the continuation and extension of the work previously carried out by Hodgins et al [13,14], which proposed a mechanism where the DEAs were combined with a buckled beam with a cross shape. In Hodgins et al, the buckled beam was used as a negative rate bias spring, which could improve the actuation stroke of the conical DE actuators.…”

Section: Designmentioning

confidence: 87%

Design of a compact bistable mechanism based on dielectric elastomer actuators

2015

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Bistable mechanisms are widely used in the applications where two stable positions must be held for long time without energy consumption. The main advantage of bistable mechanisms is a sensible reduction in bulkiness and energy cost. Among the possible active triggering systems, dielectric elastomer actuators (DEAs) are gaining attention, for their efficiency and strain rate, as a viable alternative to traditional technologies. In the present work, a novel design of a bistable system is proposed, counting on a cross-like shape bistable element coupled with two axially arranged conical DEAs. Analytical and FEM models have been used to implement and analyze the behavior of the single components and the final coupled system. The obtained results confirm the feasibility of the switching process between the equilibrium points and the capability to capture and numerically describe the interactions between the actuators and the bistable beams. A specific device has been finally envisaged to exemplify the possibility to develop a light-weight and compact system able to sustain and passively maintain a linear displacement which equals the 46 % of its own total length

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“…12. Comparison of a standard PI controller (C1) with its modified version able to exploit the self-supporting (C1e) [36].…”

Section: A Modeling and Control Of Msma Actuatorsmentioning

confidence: 99%

“…The main causes of nonlinearity in DEAP are the nonlinear actuation principle in (2), the hyperelastic behavior of polymers, the effects of the biasing system, the kinematics of the actuator configuration, and the hysteresis. The hysteresis is mostly caused by internal behaviors of the DEAP membrane and the electrodes, and it can be enlarged in case of a NBS biasing system, which, as mentioned, can also generate bi-stable operation [36]. Moreover, the sensitivity of polymeric materials to environmental conditions and the aging, which are typically not taken into account in the control-oriented models, introduce additional uncertainties, which strongly motivate the development of closed loop control algorithms for their compensation.…”

Section: B Modeling and Control Of Deap Actuatorsmentioning

confidence: 99%

Modeling and control of innovative smart materials and actuators: A tutorial

Riccardi

Rizzello

Naso

et al. 2014

2014 IEEE Conference on Control Applications (CCA)

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The need for mechatronic devices that are lightweight, less cumbersome and able to produce small, quick and precise movements or forces is ever increasing in many fields of engineering. Many recent design solutions are based on electrically, magnetically or thermally activated materials, often referred to as smart materials. This tutorial paper overviews the main properties and the resulting applications of two recently discovered smart materials, magnetic shape memory alloys (MSMAs) and electroactive polymers (EAPs), which have complementary characteristics and seem suitable to overcome some of the inherent limitations of other materials widely used in industrial applications, such as piezoelectric ceramics. As many other smart materials, MSMAs and EAPs exhibit nonlinear, hysteretic and time-varying behaviors, and therefore this tutorial discusses the main ways to model and effectively compensate these critical issues with advanced control strategies.

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Modeling and experimental validation of a bi-stable out-of-plane DEAP actuator system

Cited by 37 publications

References 25 publications

Multi-functional dielectric elastomer artificial muscles for soft and smart machines

Multi-functional dielectric elastomer artificial muscles for soft and smart machines

Design of a compact bistable mechanism based on dielectric elastomer actuators

Modeling and control of innovative smart materials and actuators: A tutorial

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