Fully Automated Fabrication of Twisted Coiled Polymer Actuators with Parameter Control (original) (raw)

Multifunctional electroelastomer rolls and their application for biomimetic walking robots

Smart Structures and Materials 2002: Industrial and Commercial Applications of Smart Structures Technologies, 2002

Dielectric elastomer artificial muscles (electroelastomers) have been shown to exhibit excellent performance in a variety of actuator configurations. By rolling highly prestrained electroelastomer films onto a central compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs) that combine load bearing, actuation, and sensing functions. The rolls are compact, have a potentially high electroelastomer-to-structure weight ratio, and can be configured to actuate in several ways including axial extension and bending, and as multiple degree-of-freedom (DOF) actuators that combine both extension and bending. 1-DOF, 2-DOF, and 3-DOF MERs have all been demonstrated through suitable electrode patterning on a single monolithic substrate. The bending MER actuators can act as leg and knee joints to produce biomimetic walking that is adaptable to many environments. Results of animation and the fabrications of a robot model of a synthetic bug or animal based on the MERs are presented. A new concept for an antagonist actuator for more precise control is introduced.

Guest Editorial Introduction to the Focused Section on Biomimetics and Novel Aspects in Robotics

IEEE/ASME Transactions on Mechatronics, 2000

Mechatronic devices and systems based on so-called electroactive polymers (EAPs) represent a fast-growing and promising scientific field of research and development. EAPs consist of materials capable of changing dimensions and/or shape in response to suitable electrical stimuli. These polymers show unique properties, such as sizable electrically driven active strains or stresses, high mechanical flexibility, low density, structural simplicity, ease of processing and scalability, no acoustic noise, and, in most cases, low costs. EAPs are today studied for applications that so far have been unachievable with conventional actuation technologies, with usage spanning from the micro-to the macro-scale, in several fields, including robotics, automation, prosthetics, orthotics, artificial organs, optics, energy harvesting, and even aerospace. In an effort to disseminate current advances in the field, this Focused Section collects together a selection of papers dealing with a number of topics related to science and technology of EAPs. Following a brief introduction to the field, this Editorial provides an overview on papers dealing with EAPs published in previous issues of this journal, introduces the papers selected for this Focused Section, and highlights future trends in the field.

Representation of a conceptual design for a rectilinear motion polymer actuator

International Journal of Control Automation and Systems

A number of different alternative actuation methods have been under active development for some specific applications where the traditional electromechanical actuators are difficult to apply. Recently, many of these substitutes are trying to employ new smart materials like electroactive polymers. However most of the polymeric materials are flexible and vulnerable so that they normally can not sustain external forces. Although the materials have shown a good potential to be used for alternative actuation mechanisms, no tangible industrial application is yet presented because of the reason. A conceptual design for a rectilinear motion actuator using dielectric elastomer is presented in this article. The introduced design concept might enable to produce fairly controllable rectilinear motions for various applications and the presented prototype actuator system is fully packaged in a small unit and controlled by a standard communication interface.

Multifunctional electroelastomer roll actuators and their application for biomimetic walking robots

SPIE Proceedings, 2003

Flexible low-mass devices and mechanisms actuated by electroactive polymers

Smart Structures and Materials 1999: Electroactive Polymer Actuators and Devices, 1999

ABSTRACT Miniature, lightweight, miser actuators that operate similar to biological muscles can be used to develop robotic devices with unmatched capabilities to impact many technology areas. Electroactive polymers (EAP) offer the potential to producing such actuators and their main attractive feature is their ability to induce relatively large bending or longitudinal strain. Generally, these materials produce a relatively low force and the applications that can be considered at the current state of the art are relatively limited. This reported study is concentrating on the development of effective EAPs and the resultant enabling mechanisms employing their unique characteristics. Several EAP driven mechanisms, which emulate human hand, were developed including a gripper, manipulator arm and surface wiper. The manipulator arm was made of a composite rod with an EAP actuator consisting of a scrolled rope that is activated longitudinally by an electrostatic field. A gripper was made to serve as an end effector and it consisted of multiple bending EAP fingers for grabbing and holding such objects as rocks. An EAP surface wiper was developed to operate like a human finger and to demonstrate the potential to remove dust from optical and IR windows as well as solar cells. These EAP driven devices are taking advantage of the large actuation displacement of these materials but there is need for a significantly greater actuation force capability. Keywords: Miniature Robotics, Electroactive Polymers, Hand Simulation, EAP Actuators, Surface Wiper, EAP Gripper 1.

Electroactive polymers (EAP) low-mass muscle actuators

Smart Structures and Materials 1997: Smart Structures and Integrated Systems, 1997

Actuation devices are used for many space applications with an increasing need to reduce their size, mass, and power consumption as well as cut their cost. Existing transducing actuators, such as piezoceramics, induce limited displacement levels.

A novel biomimetic actuator system

Robotics and Autonomous Systems, 1998

The design of a biomimetic actuation system which independently modulates position and net stiffness is presented. The system is obtained by arttagonisticaUy pairing contractile devices capable of modulating their rate of geometric deformation relative to the rate of deformation of a passive elastic storage element in series with the device's input source. A mechanical model is developed and the properties of the device are investigated. The theoretical results developed are then compared with experimental evidence obtained from a simple prototype model of the system. upon similar experimental results, Alexander [2] asserts that humans store energy in their Achilles tendons and the ligaments that support the arch of the foot, and that compliant legs and feet reduce the peak forces that occur when the foot strikes the ground. In a similar vein, Cavagna et al. suggest that running is essentially bouncing.

Dielectric elastomer artificial muscle actuators: Toward biomimetic motion

2002

To achieve desirable biomimetic motion, actuators must be able to reproduce the important features of natural muscle such as power, stress, strain, speed of response, efficiency, and controllability. It is a mistake, however, to consider muscle as only an energy output device. Muscle is multifunctional. In locomotion, muscle often acts as an energy absorber, variable-stiffness suspension element, or position sensor, for example. Electroactive polymer technologies based on the electric-field-induced deformation of polymer dielectrics with compliant electrodes are particularly promising because they have demonstrated high strains and energy densities. Testing with experimental biological techniques and apparatus has confirmed that these "dielectric elastomer" artificial muscles can indeed reproduce several of the important characteristics of natural muscle. Several different artificial muscle actuator configurations have been tested, including flat actuators and tubular rolls. Rolls have been shown to act as structural elements and to incorporate position sensing. Biomimetic robot applications have been explored that exploit the muscle-like capabilities of the dielectric elastomer actuators, including serpentine manipulators, insect-like flappingwing mechanisms, and insect-like walking robots.

In pursuit of dynamic range: Using parallel coupled actuators to overcome hardware limitations

Lecture Notes in Control and Information Sciences

Dielectric elastomer artificial muscles have great potential for the creation of novel pumps, motors, and circuitry. Control of these devices requires an oscillator, either as a driver or clock circuit, which is typically provided as part of bulky, rigid, and costly external electronics. Oscillator circuits based on piezo-resistive dielectric elastomer switch technology provide a way to embed oscillatory behavior into artificial muscle devices. Previous oscillator circuits were not digital, able to function without a spring mass system, able to self-start, or suitable for miniaturization. In this paper we present an artificial muscle ring oscillator that meets these needs. The oscillator can self-start, create a stable 1 Hz square wave output, and continue to function despite degradation of the switching elements. Additionally, the oscillator provides a platform against which the performance of different dielectric elastomer switch materials can be benchmarked.

Fully Automated Fabrication of Twisted Coiled Polymer Actuators with Parameter Control (original) (raw)

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