J. D. Nam

Novel electroactive, silicate nanocomposites prepared to be used as actuators and artificial muscles

Reported herein is a newly developed nanocompositing technique that can provide an effective process tool to optimize the desirable properties of the base ionic polymer materials to be used as effective electroactive polymer (EAP) actuators and artificial muscles. We developed polymer nanocomposite (PNC) materials that incorporate clay-based layered silicates. The clay-based layered silicates were intercalated within the polymer matrix of perfluorosulfonate ionomer. A certain clay, Montmorillonite (MMT), was selected as an effective clay and was modified by a cationic surfactant in order to lower its surface energy significantly. This process gave rise to a favorable intercalation of Montmorillonite within the galleries. The obtained XRD patterns prove that the silicate layers are intercalated in a continuous polymer matrix. Such a polymer nanocomposite shows significantly improved structural and electrochemical behavior and, thus, can be successfully used as the effective base material of EAP actuators and artificial muscles.

Soft actuator for robotic applications based on dielectric elastomer: quasi-static analysis

In this paper a new soft actuator based on dielectric elastomer is proposed. The actuator, called an antagonistically-driven linear actuator (ANTLA), has the muscle-like characteristics capable of performing the motions such as forward/backward/controllable compliance. Due to its simplicity of configuration and ease of fabrication, it has the advantage to be scale-independently implemented in meso- or micro-scale robotic applications. Its basic concepts are introduced and a quasi-static analysis is performed with experimental verifications.

Wearable Fingertip Tactile Display

Tactile sensation is one of the most important sensory functions for human perception of objects. Recently, there have been many technical challenges in the field of tactile sensing as well as tactile display. In this paper, we propose an innovative tactile display device based on soft actuator technology with electroactive polymer (EAP). This device offers advantageous features over existing devices with respect to intrinsic flexibility, softness, ease of fabrication and miniaturization, high power density, and cost effectiveness. In particular, it can be adapted to various geometric configurations because it possesses structural flexibility, so it can be worn on any part of the human body such as finger, palm, and arm etc. It can be extensively applied as a wearable tactile display, a Braille device for the visually disabled, and a human interface in the future. A new design of the flexible actuator is proposed and its basic operational principles are discussed. In addition, a wearable tactile display device with 4times5 actuator array (20 actuator cells) is developed and its effectiveness is confirmed

Soft actuator for robotic applications based on dielectric elastomer: dynamic analysis and applications

In this paper a new soft actuator based on dielectric elastomer is proposed. The actuator, called an antagonistically-driven linear actuator (ANTLA), has the muscle-like characteristics capable of performing the motions such as forward/backward/controllable compliance. In this paper, its dynamic analysis is performed with experimental verifications, and applications for robotic actuating devices are introduced.

Wearable tactile display based on soft actuator

Tactile sensation is one of the most important sensory functions for human perception of objects. Recently, there have been many technical challenges in the field of tactile sensing as well as tactile display. In this paper, we propose an innovative tactile display device based on soft actuator technology with electroactive polymer (EAP). This device offers advantageous features over existing devices with respect to intrinsic flexibility, softness, ease of fabrication and miniaturization, high power density, and cost effectiveness. In particular, it can be adapted to various geometric configurations because it possesses structural flexibility, so it can be worn on any part of the human body such as finger, palm, and arm etc. It can be extensively applied as a wearable tactile display, a Braille device for the visually disabled, and a human interface in the future. A new design of the flexible actuator is proposed and its basic operational principles are discussed. In addition, a tactile display device with 10times10 actuator array (100 actuator cells) is developed and its effectiveness is confirmed

Development of dielectric elastomer driven micro-optical zoom lens system

Normally, various micro-scale devices adopt electromechanical actuators for their basic mechanical functions. Those types of actuators require a complicated power transfer system even for generating a tiny scale motion. Since the mechanical power transfer system for the micro-scale motion may require many components, the system design to fit those components into a small space is always challenging. Micro-optical zoom lens systems are recently popularly used for many portable IT devices such as digital cameras, camcorder, and cell phones, Noting the advantages of EAP actuators over the conventional electromechanical counterparts in terms of simple actuator mechanisms, a micro-optic device that is driven with the EAP actuator is introduced in the present work. EAP material selection, device design and fabrication will be also delineated.

Fabrication and characterization of linear motion dielectric elastomer actuators

This paper presents a new artificial muscle actuator produced from dielectric elastomer, called Tube-Spring Actuator(TSA). The new actuator construction includes two steps: the first part is a cylindrical actuator manufactured with dielectric elastomer and the second is a compressed spring inserted inside the tube. An inner spring is used to maximize the axial deformation while constraining the radial one. This unique design enables linear actuation with the largest strain of active length up to 14% without any additional means. As a result this actuator was applied to a robot hand. This study lays the foundation for the future work on dielectric polymer actuator.

Digital polymer motor for robotic applications

In this paper we present a packaged actuator to be applied for micro- and macro- robotic applications. The actuator is based on polymer dielectrics, and intrinsically has muscle-like characteristics capable of performing motions such as forward/backward/controllable compliance. The actuator is featured in several aspects such as simplicity and lightness in weight, cost-effectiveness, multiple DOF-actuation, and digital interface. In this paper, its basic concepts are briefly introduced and the issues about design, fabrication and applications are discussed.

Synthesis of new solid polymer electrolyte and actuator based on PEDOT/NBR/ionic liquid

The conducting polymer actuator was presented. The solid polymer electrolyte based on nitrile rubber (NBR) activated with different ionic liquids was prepared. The three different grades of NBR films were synthesized by emulsion polymerization with different amount of acrylonitrile, 23, 35, and 40 mol. %, respectively. The effect of acrylonitrile content on the ionic conductivity and dielectric constant of solid polymer electrolytes was characterized. A conducting polymer, poly(3,4-ethylenedioxythiophene) (PEDOT), was synthesized on the surface of the NBR layer by using a chemical oxidation polymerization technique, and room temperature ionic liquids (RTIL) based on imidazolium salts, e.g. 1-butyl-3-methyl imidazolium X [where X= BF4-, PF6-, (CF3SO2)2N-], were absorbed into the composite film. The effects of the anion size of the ionic liquids on the displacement of the actuator were examined. The displacement increased with increasing the anion-size of the ionic liquids.