Pneumatic Artificial Rubber Muscle Research Articles

Development of Pneumatic Artificial Rubber Muscle Using Segmented Shape-Memory Polymer Sheets

We have developed a pneumatic artificial rubber muscle using two shape-memory polymer (SMP) sheets. We attached the SMP sheets to a linear pneumatic artificial rubber muscle. Utilizing the large difference in the elastic modulus below and above the glass transition temperature, the shape fixity and shape recovery of SMPs, the bending direction and the initial shape can be changed. In this study, in order to increase the bending motion range, we developed a segmented SMP sheet with embedded electrical heating wires, and evaluated its mechanical properties using bending and tensile tests. Moreover, we attached such sheets to an artificial muscle and evaluated the bending motion. Bending tests showed that segmenting the SMP sheets greatly reduced their bending stiffness. In tensile tests at temperatures below the glass transition temperature, it was found that the artificial muscle with the attached sheet withstood high elongating loads without failure. Attachment of such segmented SMP sheets to an artificial muscle resulted in an increased bending angle. Through isotonic and isometric tests, we showed that the prototype actuator could bend in two directions.

Two-link Manipulator Driven by a Pair of Antagonistic Rubber Artificial Muscle

Pneumatic rubber artificial muscles have been extensively researched as a driving device capable of soft movements that are compatible with humans, and are expected to be applied to human friendly robots. However, it is difficult in principle to achieve high-precision positioning and high-rigidity position retention due to low stiffness and delayed response as a result of air compressibility. Normally, a 2-link manipulator requires 4 (2 pairs) artificial muscles, but here, by attaching two MR brakes to each axis and switching the drive shaft, a manipulator that controls a 2-link manipulator with 2 (1 pair) artificial muscles, is proposed.

Peristaltic Mixing Pump Based on Bowel Peristalsis Using Pneumatic Artificial Rubber Muscles and Prospects for Practical Applications

This letter proposes a peristaltic mixing pump based on bowel peristaltic motion driven by soft pneumatic actuators. Furthermore, various practical applications using the peristaltic mixing pump are introduced, such as mixing and conveying processes for solid rocket fuel production and lifting conveyance of excavated soil and sand during the construction process. First, the bowel peristaltic motion mechanism is introduced from the anatomical perspective. Next, the construction of the peristaltic mixing pump and its actuation mechanism are presented. Finally, the application and prospects of peristaltic mixing pumps are described.

Development of Variable Viscoelastic Joint Module Performance Evaluation and Proposal of Application Examples

With the diversification of robots, modularization of robots has been attracting attention. In our previous study, we developed a robot that mimics the principle of human joint drive using a straight-fiber-type pneumatic rubber artificial muscle (“artificial muscle”) and a magnetorheological fluid brake (“MR brake”). The variable viscoelastic joints have been modularized. Therefore, this paper evaluates the basic characteristics of the developed Joint Module, characterizes the variable viscoelastic joint, and compares it with existing modules. As basic characteristics, we confirmed that the Joint Module has a variable viscoelastic element by experimentally verifying the joint angle, stiffness, viscosity, and tracking performance of the generated torque to the command value. As a characteristic evaluation, we verified the change in motion and response to external disturbances due to differences in driving methods through simulations and experiments and proved the strength of the variable viscoelastic joint against external disturbances, which is a characteristic of variable viscoelastic joints. Based on the results of the basic characterization and the characterization of the variable viscoelastic drive joint, we discussed what kind of device the Joint Module is suitable to be applied to and clarified the position of the variable viscoelastic joint as an actuator system.

Development of walking rehabilitation device using planar link mechanism and pneumatic rubber artificial muscle

In Japan today, the aging of the population is progressing, and there is a concern that the number of elderly people who will have a trouble walking will increase. Rehabilitation of medical and welfare services are required to solve this problem, but it will be concerned to be difficult to deal with this problem due to a shortage of human resources and an increase in the number of elderly people. Therefore, there is a need to develop a walking rehabilitation device that can be handled by the elderly alone. Authors has been developing walking aids and rehabilitation devices using linkages. These devices do not require a control system or an external power source, and are designed with an emphasis on simplification and cost reduction of the devices. However, if it is designed with only a mechanism, the operation of the device may become unstable, which has been a problem. Therefore, authors aim to improve the stability of the device by newly using a pneumatic rubber artificial muscle as an actuator and assisting the operation of the mechanism. In this research, on the premise that a pneumatic rubber artificial muscle is used as an actuator, authors will develop a device that rehabilitates the interlocking movement of three leg joints with a one degree-of-freedom link mechanism. The aim of this study is to verify whether the characteristics of artificial muscles such as flexibility, high output density, and contractile movement are suitable for walking rehabilitation equipment.

平面リンク機構と空気圧ゴム人工筋肉を用いた歩行リハビリ装置の試作および評価

In Japan today, the aging of the population is progressing, and there is a concern that the number of elderly people who will have a trouble walking will increase. Rehabilitation of medical and welfare services are required to solve this problem, but it will be concerned to be difficult to deal with this problem due to a shortage of human resources and an increase in the number of elderly people. Therefore, there is a need to develop a walking rehabilitation device that can be handled by the elderly alone. Authors has been developing walking aids and rehabilitation devices using linkages. These devices do not require a control system or an external power source, and are designed with an emphasis on simplification and cost reduction of the devices. However, if it is designed with only a mechanism, the operation of the device may become unstable, which has been a problem. Therefore, authors aim to improve the stability of the device by newly using a pneumatic rubber artificial muscle as an actuator and assisting the operation of the mechanism. In this research, on the premise that a pneumatic rubber artificial muscle is used as an actuator, authors will develop a device that rehabilitates the interlocking movement of three leg joints with a one degree-of-freedom link mechanism. In this research, Authors will use an actual machine to evaluate whether the characteristics of the artificial muscle, such as flexibility, high output density, and contractile motion, are suitable for walking rehabilitation equipment.

A Study on Development and Control of Antagonistic Muscle Joint Structure Using Pneumatic Rubber Artificial Muscle and Non-Circular Pulley

A Study on Development and Control of Antagonistic Muscle Joint Structure Using Pneumatic Rubber Artificial Muscle and Non-Circular Pulley

Development of a Knee Joint Assistive Orthosis Using Pneumatic Rubber Artificial Muscles for Maintaining a Half-Sitting Posture

Development of a Knee Joint Assistive Orthosis Using Pneumatic Rubber Artificial Muscles for Maintaining a Half-Sitting Posture

Characteristics of Pneumatic Artificial Rubber Muscle Using Two Shape-Memory Polymer Sheets

We have developed a pneumatic artificial rubber muscle having a bending direction that can be changed using two shape-memory polymer (SMP) sheets, the stiffness of which depends on the temperature. In the present study, we attached two SMP sheets with embedded electrical heating wires to both sides of a pneumatic artificial rubber muscle in order to realize multidirectional actuation and evaluated the basic characteristics of the artificial muscle. The actuator is based on the design of a conventional curved-type artificial rubber muscle. Since only a heated SMP sheet becomes soft, the rigid SMP sheet inhibits the extension of the side of the actuator. Therefore, bending motion can be induced when air is supplied to the internal bladder. By controlling the temperature of the SMP sheets, the bending direction of the prototype actuator could be changed. Namely, three kinds of motions, such as two-directional bending and axial extension, became possible. Moreover, we improved the manufacturing method and the structure of the artificial muscle, such as the stitching method and the SMP sheet thickness, and evaluated the characteristics of the two-directional bending and the axial extension motions of the prototype actuator. We also calculated the theoretical values and compared these values with the experimental results. Furthermore, we examined the application of the actuators to a robot hand. Using the two-directional motion of the actuator, the proposed robot hand can grasp either small or large objects. The experimental results conducted using this prototype confirm the feasibility of the newly proposed actuator.

Development of a robot hand based on the musculoskeletal system using pneumatic rubber artificial muscle

Development of a robot hand based on the musculoskeletal system using pneumatic rubber artificial muscle

Development of components in icosahedral self-distortion robot using bending pneumatic rubber artificial muscles. And robot driving experiments.

Development of components in icosahedral self-distortion robot using bending pneumatic rubber artificial muscles. And robot driving experiments.

Development and control of cord-like manipulator using bending type pneumatic rubber artificial muscles

Development and control of cord-like manipulator using bending type pneumatic rubber artificial muscles

Exploring solutions to assist finger rehabilitation with flexibility

Motivated by the need to help those people whose hands and fingers are incapacitated due to injuries or birth defects, the curved-type pneumatic artificial rubber muscle is discussed in this paper, which is shown to be more flexible and convient than traditional motor-driven soft robotic devices for hand rehabilitation and assistance if designed correctly. When people are injured, their finger joints become stiff and not be able to fully flex. Thus, an assisting device is needed. Machine-based hand exoskeleton for rehabilitation uses hardware and hard components, which carries the risk of furthering the injuries when the exoskeleton breaks or exceeds its driving capacity. In comparison, air-pneumatics driven hand rehabilitation device composed of flexible air muscle not only curves smoother, but also weighs lighter and can be designed as a carry-on, providing safety, utility, and comfortability. Several experiments and researches were run to determine the best structure and air-pressure to suit such purposes. Instead of the traditional button-pressing panel, Neuron-Muscular Transmission (NMT) - a detectable chemical signal - is used to activate the inflation and deflation of the device, therefore making the device thought-driven. In the end, Flexible Pneumatic System (FPS) is created to improve hand rehabilitation and supportive exoskeleton devices.

Development of Power Assist Device Using Pneumatic Artificial Rubber Muscle

Development of Power Assist Device Using Pneumatic Artificial Rubber Muscle

Development of Remote Controlled Robot with Pneumatic Artificial Rubber Muscles for Hydraulic Excavator

Development of Remote Controlled Robot with Pneumatic Artificial Rubber Muscles for Hydraulic Excavator

A Motion Control of Soft Gait Assistive Suit by Gait Phase Detection Using Pressure Information

Power assistive devices have been developed in recent years. To detect the wearer’s motion, conventional devices require users to wear sensors. However, wearing many sensors increases the wearing time, and usability of the device will become worse. We developed a soft gait assistive suit actuated by pneumatic artificial rubber muscles (PARMs) and proposed its control method. The proposed suit is easy to wear because the attachment unit does not have any electrical sensors that need to be attached to the trainee’s body. A target application is forward walking exercise on a treadmill. The control unit detects the pre-swing phase in the gait cycle using the pressure information in the calf back PARMs. After the detection, the suit assists the trainee’s leg motion. The assist force is generated by the controlled PARM pressure, and the pressure input time is changed appropriately considering the gait cycle time. We conducted walking experiments; (1) verifies the proposed control method works correctly, and (2) verifies whether the gait assistive suit is effective for decreasing muscular activity. Finally, we confirmed that the accurate phase detection can be achieved by using the proposed control method, and the suit can reduce muscular activity of the trainee’s leg.

Prolonging the fatigue life of the Straight fiber type pneumatic artificial muscle by the strain-induced crystallization of Natural rubber

Pneumatic rubber artificial muscle is attracting attention as an actuator having high cooperativeness with human because of its feature of being flexible and lightweight. The authors have developed Straight fiber type pneumatic artificial muscle (SF-ARM), which is a high power, highly displaced pneumatic rubber artificial muscle. Although SF-ARM has excellent contraction characteristics, it has a problem of short fatigue life. Therefore, in this study, focusing on strain-induced crystallization of natural rubber, the fatigue life of SF-ARM has been extended. First, strain-induced crystallization of natural rubber were confirmed by wide angle X-ray diffraction. Next, analysis of strain concentration in the vicinity of the crack was performed by the finite element method. Finally, a fatigue life test of SF-ARM was carried out to confirm the effect of prolonging the fatigue life by using strain-induced crystallization.

Development of a muscle strength training device with variable resistance using pneumatic artificial rubber muscle

Development of a muscle strength training device with variable resistance using pneumatic artificial rubber muscle

Structural Improvement and Evaluation of Pneumatic Artificial Rubber Muscle Using Shape-memory Polymer Sheets

Structural Improvement and Evaluation of Pneumatic Artificial Rubber Muscle Using Shape-memory Polymer Sheets

Modeling of pneumatic artificial rubber muscle using Bouc-Wen model

Modeling of pneumatic artificial rubber muscle using Bouc-Wen model