scholarly journals Smart Devices Based on the Soft Actuator with Nafion-Polypropylene-PDMS/Graphite Multilayer Structure

2020 ◽  
Vol 10 (5) ◽  
pp. 1829
Author(s):  
Yao Wei ◽  
Shihao Li ◽  
Xiaofan Zhang ◽  
Yanjun Fu ◽  
Kejian Chen
Keyword(s):  
Fast Response ◽  
Smart Devices ◽  
Asymmetric Structure ◽  
Soft Sensors ◽  
Bending Angle ◽  
Soft Actuator ◽  
Stimulus Responsive ◽  
Potential Applications ◽  
Control Circuits ◽  
Soft Actuators

The demand for multi-functional soft actuators with simple fabrication and fast response to multiple stimuli is increasing in the field of smart devices. However, for existing actuators that respond to a single stimulus, it is difficult to meet the requirements of application diversity. Herein, a type of multi-stimulus responsive soft actuator based on the Nafion-Polypropylene-polydimethylsiloxane (PDMS)/Graphite multilayer membranes is proposed. Such actuators have an excellent reversible response to optical/thermal and humidity stimulation, which can reach a 224.56° bending angle in a relative humidity of 95% within 5 s and a maximum bending angle of 324.65° in 31 s when the platform temperature is 80 °C, and has a faster response (<0.5 s) to optical stimuli, as an asymmetric structure allows it to bend in both directions. Based on such an actuator, some applications like flexible grippers and switches to carry items or control circuits, bionic flytraps to capture and release “prey”, have also been developed and studied. These provide potential applications in the fields of soft sensors, artificial skin and flexible robots.

scholarly journals Research on performance of rigid-hoop-reinforced multi-DOF soft actuator

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110267
Author(s):  
Jin Sun ◽  
Daozhou Zhang ◽  
Yang Zhang ◽  
Xinglong Zhu ◽  
Juntong Xi ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Silicone Rubber ◽  
Spring Steel ◽  
High Load ◽  
The Body ◽  
Load Carrying Capacity ◽  
Bending Angle ◽  
Soft Actuator ◽  
Load Carrying ◽  
Soft Actuators

In order to improve the bearing capacity of soft actuators, this article presents the development of the rigid-hoop-reinforced (spring or steel hoop) multi-DOF soft actuator. The actuator is composed of a rotary module with spring reinforcement on the silicone rubber-based body and a bending module with steel hoop reinforcement on the body. Compared with fiber-reinforced actuators, the bearing capacities of rigid-hoop-reinforced actuators made of 65Mn spring steel are improved. The radial and the axial bearing capacity for the bending module and the rotary module is raised by 29.6%, 28.2%, 30.6%, 49.6% respectively; under the same pressure, the spring-reinforced interval increases the maximum rotary angle of the rotary module, the steel hoop-reinforced interval increases the maximum bending angle of the bending module; with the same reinforcement type, the bending module with reinforcement interval of 10 mm has good bending characteristics that the bending angle changes with the pressure gently; the lower the hardness of silicone rubber base body, the better the adaptability and flexibility of the actuator, and the higher the hardness, the greater the bearing capacity of the actuator. Due to the above advantages, the rigid-hoop-reinforced multi-DOF soft actuator can be applied to medical devices which need high load-carrying capacity.

Multiple Inputs-Single Accumulated Output Mechanism for Soft Linear Actuators

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Kyeong Ho Cho ◽  
Ho Moon Kim ◽  
Youngeun Kim ◽  
Sang Yul Yang ◽  
Hyouk Ryeol Choi
Keyword(s):  
Artificial Muscle ◽  
Operating Mode ◽  
Robotic Arm ◽  
Soft Actuator ◽  
Wearable Robots ◽  
Working Principle ◽  
Linear Actuators ◽  
Soft Actuators ◽  
Muscle Actuators ◽  
Further Development

Soft linear actuators (SLAs) such as shape memory alloy (SMA) wires, pneumatic soft actuators, dielectric elastomer actuator, and twisted and coiled soft actuator (TCA) called artificial muscle actuators in general, have many advantages over the conventional actuators. SLAs can realize innovative robotic technologies like soft robots, wearable robots, and bionic arms in the future, but further development is still needed in real applications because most SLAs do not provide large displacement or force as needed. This paper presents a novel mechanism supplementing SLAs by accumulating the displacement of multiple SLAs. It adopts the principle of differential gears in reverse. Since the input units of the mechanism are extensible, more displacement can be accumulated by increasing the number of the input units as many as needed. The mechanism is basically used to accumulate displacements, but can be used to accumulate forces by changing its operating mode. This paper introduces the design and working principle of the mechanism and validates its operation experimentally. In addition, the mechanism is implemented on a robotic arm and its effectiveness is confirmed.

Examining the Coiling Motion of Soft Actuators Reinforced With Tilted Helix Fibers

2018 ◽  
Author(s):  
Ryan Geer ◽  
Suyi Li
Keyword(s):  
Longitudinal Axis ◽  
Robotic Manipulation ◽  
Proof Of Concept ◽  
Soft Actuator ◽  
Kevlar Fiber ◽  
New Family ◽  
End Caps ◽  
Soft Actuators ◽  
Unique Cell ◽  
Cell Wall Architecture

This study aims to examine the coiling and uncoiling motion of a soft pneumatic actuator reinforced with tilted helix fibers. Coiling motion can be quite useful for robotic manipulation and locomotion purposes. This research proposes and investigates a novel actuator that is inspired and derived from the unique cell wall architecture in the seed appendage of Stork’s Bill plant (Erodium Gruinum). These plant cells are reinforced by cellulose fibers distributed in a tilted helix pattern — helixes that are tilted at a certain angle with respect to the longitudinal axis of the cell. As a result, the seed appendage can coil and uncoil via a combination of twisting and bending. This paper discusses the design, fabrication, and testing of a soft actuator that can mimic this sophisticated motion. This actuator consists of Kevlar fiber thread wrapped around a silicon rubber body that has the shape of a tube. The tube will be capped at both ends so that it can be pressurized internally to induce motion. Once the design parameter has been chosen, the soft actuator are fabricated by 1) designing and 3D printing molds, 2) tube casting and fiber wrapping, and 3) creating the end caps for pressure sealing. Carefully executing these fabrication steps is essential because any errors could give undesired deformation. Several soft actuators prototypes are fabricated based on different design choices regarding the actuator radius, tube wall thickness, and the number of tilted helix fibers (aka. fiber coverage). Proof-of-concept tests show that these actuator prototypes can indeed exhibit a combined twisting and bending under internal pressurization: all are the necessary receipts to achieve the coiling and uncoiling motion. Result of this paper can pave the way for a new family of soft actuators capable of unprecedented and sophisticated actuation motions, which are particularly appealing for soft robot application.

Design and optimization of actuator for multi-joint soft rehabilitation glove

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xinjie Wang ◽  
Yan Cheng ◽  
Huadong Zheng ◽  
Yihao Li ◽  
Caidong Wang
Keyword(s):  
Constitutive Model ◽  
Element Model ◽  
Longitudinal Section ◽  
Bending Test ◽  
Hand Rehabilitation ◽  
Content Type ◽  
Design And Optimization ◽  
Soft Actuator ◽  
New Type ◽  
Soft Actuators

Purpose Currently, rehabilitation medical care is expensive, requires a large number of rehabilitation therapist and which can only limit in the fixed location. In addition, there is a lack of research on the structure optimization and theoretical analysis of soft actuators for hand rehabilitation. In view of the problems above, this paper aims to propose a cheap, portable, wearable soft multiple joints rehabilitation glove. Design/methodology/approach First, this paper determined the hyperelastic constitutive model by material tensile test. Second, the soft actuator’s internal longitudinal section shape was optimized through the comparison of three diverse chamber structures. Meanwhile, the motion model of the soft actuator is established by the finite element model analysis method. Then, this paper established the constitutive model of the soft actuator according to the torque equilibrium equation and analyzed the relationship between the soft actuator’s bending angle and the input air pressure. This paper has verified that the theoretical model is correct through the soft actuator bending test. Finally, rehabilitation gloves were manufactured according to the model and the rehabilitation performance and grasping ability of gloves were verified through experiments. Findings The optimization results show that the internal semicircular cavity has better performance. Then, the actuator performance is better after adding the external arc structure and optimizing the physical dimension. The experimental results show that the trajectory of the actuator conforms to the mathematical model and rehabilitation gloves can meet the needs of rehabilitation treatment. Practical implications Rehabilitation gloves made of actuators can help patients with hand dysfunction in daily rehabilitation training. Then, it can also assist patients with some fine and complicated hand movements. Originality/value This paper proposes a new type of soft rehabilitation glove, which is composed of new soft actuators and adapting pieces. The new actuator is small enough to be fitted to the knuckle of the glove to move each joint of the finger.

Evaluation of a Suitable Material for Soft Actuator Through Experiments and FE Simulations

2022 ◽  
pp. 339-353
Author(s):  
Elango Natarajan ◽  
Muhammad Rusydi Muhammad Razif ◽  
AAM Faudzi ◽  
Palanikumar K.
Keyword(s):  
Tensile Modulus ◽  
Cylindrical Tube ◽  
Fast Response ◽  
Nonlinear Material ◽  
Element Analysis ◽  
Elongation At Break ◽  
Multi Wall Carbon Nanotubes ◽  
Suitable Material ◽  
The Finite Element Analysis ◽  
Soft Actuators

Soft actuators are generally built to achieve extension, contraction, curling, or bending motions needed for robotic or medical applications. It is prepared with a cylindrical tube, braided with fibers that restrict the radial motion and produce the extension, contraction, or bending. The actuation is achieved through the input of compressed air with a different pressure. The stiffness of the materials controls the magnitude of the actuation. In the present study, Silastic-P1 silicone RTV and multi-wall carbon nanotubes (MWCNT) with reinforced silicone are considered for the evaluation. The dumbbell samples are prepared from both materials as per ASTM D412-06a (ISO 37) standard and their corresponding tensile strength, elongation at break, and tensile modulus are measured. The Ogden nonlinear material constants of respective materials are estimated and used further in the finite element analysis of extension, contraction, and bending soft actuators. It is observed that silicone RTV is better in high strain and fast response, whereas, silicone/MWCNT is better at achieving high actuation.

scholarly journals Application and Analysis of an Ionic Liquid Gel in a Soft Robot

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Chenghong Zhang ◽  
Bin He ◽  
Zhipeng Wang ◽  
Yanmin Zhou ◽  
Aiguo Ming
Keyword(s):  
Ionic Liquid ◽  
Uv Light ◽  
Electroactive Polymers ◽  
Electroactive Polymer ◽  
Soft Robot ◽  
Polymer Gel ◽  
Basic Module ◽  
Soft Actuator ◽  
New Type ◽  
Soft Actuators

Due to their light weight, flexibility, and low energy consumption, ionic electroactive polymers have become a hotspot for bionic soft robotics and are ideal materials for the preparation of soft actuators. Because the traditional ionic electroactive polymers, such as ionic polymer-metal composites (IPMCs), contain water ions, a soft actuator does not work properly upon the evaporation of water ions. An ionic liquid polymer gel is a new type of ionic electroactive polymer that does not contain water ions, and ionic liquids are more thermally and electrochemically stable than water. These liquids, with a low melting point and a high ionic conductivity, can be used in ionic electroactive polymer soft actuators. An ionic liquid gel (ILG), a new type of soft actuator material, was obtained by mixing 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), hydroxyethyl methacrylate (HEMA), diethoxyacetophenone (DEAP) and ZrO2 and then polymerizing this mixture into a gel state under ultraviolet (UV) light irradiation. An ILG soft actuator was designed, the material preparation principle was expounded, and the design method of the soft robot mechanism was discussed. Based on nonlinear finite element theory, the deformation mechanism of the ILG actuator was deeply analyzed and the deformation of the soft robot when grabbing an object was also analyzed. A soft robot was designed with the soft actuator as the basic module. The experimental results show that the ILG soft robot has good driving performance, and the soft robot can grab a 105 mg object at an input voltage of 3.5 V.

scholarly journals An Overview of Novel Actuators for Soft Robotics

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 48 ◽  
Author(s):  
Pinar Boyraz ◽  
Gundula Runge ◽  
Annika Raatz
Keyword(s):  
Meta Analysis ◽  
Performance Criteria ◽  
Soft Robotics ◽  
Magnetic Actuators ◽  
Technological Readiness ◽  
Potential Applications ◽  
Readiness Level ◽  
Comprehensive Comparison ◽  
Electro Magnetic ◽  
Soft Actuators

In this systematic survey, an overview of non-conventional actuators particularly used in soft-robotics is presented. The review is performed by using well-defined performance criteria with a direction to identify the exemplary and potential applications. In addition to this, initial guidelines to compare the performance and applicability of these novel actuators are provided. The meta-analysis is restricted to five main types of actuators: shape memory alloys (SMAs), fluidic elastomer actuators (FEAs), shape morphing polymers (SMPs), dielectric electro-activated polymers (DEAPs), and magnetic/electro-magnetic actuators (E/MAs). In exploring and comparing the capabilities of these actuators, the focus was on eight different aspects: compliance, topology-geometry, scalability-complexity, energy efficiency, operation range, modality, controllability, and technological readiness level (TRL). The overview presented here provides a state-of-the-art summary of the advancements and can help researchers to select the most convenient soft actuators using the comprehensive comparison of the suggested quantitative and qualitative criteria.

Design of a Deformable Smart Tire Using Soft Actuator

2019 ◽  
Author(s):  
Vidya K. Nandikolla ◽  
Michael Costa ◽  
Nathan Boyd ◽  
Gilberto Rosales
Keyword(s):  
Force Feedback ◽  
Design Procedure ◽  
Nickel Titanium ◽  
Operating Conditions ◽  
Mechanical Modeling ◽  
Soft Actuator ◽  
Voltage Signal ◽  
3D Printed ◽  
Primary Focus ◽  
Soft Actuators

Abstract The unique functional properties of nickel-titanium Shape Memory Alloys (SMA) enable them to be used as actuators. This research paper demonstrates theoretically and experimentally the feasibility of using SMA in smart tires for a mobile robot. The design procedure for SMA as a coil spring actuator for a soft deformable wheel is described. The primary focus is the mechanical modeling, manufacturing, and system dynamics of a soft deformable wheel. The 3D printed soft tire exploits the capabilities of the SMA actuation using a voltage signal. The printed components are activated and integrated with electromechanical circuit for wireless communication system. The performance of the force feedback control system is evaluated at different operating conditions to demonstrate the shape-changing characteristic of the smart tire. The developed prototype is designed to propel forward and backward on flat and uneven surface. The experimental results obtained demonstrate the potential of SMA as soft actuators, its benefits and limitations as flexible systems.

A Micro Pump Driven by Conducting Polymer Soft Actuator Based on Polypyrrole

2009 ◽  
Author(s):  
Yoshitaka Naka ◽  
Masaki Fuchiwaki ◽  
Kazuhiro Tanaka
Keyword(s):  
Energy Consumption ◽  
Conducting Polymer ◽  
Low Voltage ◽  
Flow Rates ◽  
Soft Actuator ◽  
Micro Pump ◽  
Consumption Rates ◽  
Basic Characteristics ◽  
Soft Actuators ◽  
Transport Fluid

Micro pumps with various driving systems have been developed and they have been carried out with experimental and numerical approaches so far. The authors propose a micro pump with soft actuators by conducting polymers as a driving source. The purpose of the present study is to develop the micro pump driven by conducting polymer soft actuator based on polypyrrole and to clarify the basic characteristics of the micro pump. Especially, we measure the flow rates, delivery heads and energy consumption of the micro pump driven by conducting polymer soft actuators and compare these results with those of the conventional micro pumps. The micro pump driven by a conducting polymer soft actuator can transport fluids in one direction without backflow by two soft actuators with opening and closing movement. Furthermore, wider ranges of flow rates are obtained with this micro pump and greater maximum delivery heads are obtained by them Moreover, the influence of the viscosity of the transport fluid was small and the micro pump driven by the conducting polymer soft actuator can transport fluid even with the viscosity that is 400 times as great as that of water in addition. The energy consumption rates of our micro pump are dramatically lower than those of the conventional micro pumps. This is because a conducting polymer soft actuator drives with a low voltage and a micro pump with low energy consumption is realized here.

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