Macroporous smart gel based on pH-sensitive polyacrylic polymer for the development of large size artificial muscle with linear contraction

Soft Matter ◽  
2021 ◽  
Author(s):  
Vincent Mansard
Keyword(s):  
Soft Matter ◽  
Artificial Muscle ◽  
Ph Sensitive ◽  
Artificial Muscles ◽  
Linear Contraction ◽  
Large Size ◽  
Polyacrylic Polymer ◽  
The Revolution

The physics of soft matter can contribute to the revolution in robotics and medical prostheses.These two fields requires the development of artificial muscles with behavior close to the biologicalmuscle. Today,...

Luminal perfusion of isolated gastric glands

1994 ◽  
Vol 266 (4) ◽  
pp. C1013-C1027 ◽  
Author(s):  
S. J. Waisbren ◽  
J. Geibel ◽  
W. F. Boron ◽  
I. M. Modlin
Keyword(s):  
Ph Sensitive ◽  
Renal Tubules ◽  
Gastric Glands ◽  
Ph Gradients ◽  
Large Size ◽  
Isolated Gastric Glands ◽  
Buffering Power ◽  
Luminal Perfusion ◽  
Ethanesulfonic Acid ◽  
Fast Perfusion

We have extended to rabbit gastric glands the technique for perfusing single isolated renal tubules. We isolated glands by hand dissection and used concentric glass pipettes to hold them and perfuse their lumina. Parietal cells (PCs), which tended to be located toward the gland opening, were identified by their pyramidal shape, large size, and autofluorescence. Chief cells (CCs) were identified by their round shape and smaller size. In some experiments, we perfused the lumen with hydroxypyrenetrisulfonate, a pH-sensitive fluorophore, at pH 7.4 and used digital image processing to monitor luminal pH (pH1). Solutions were buffered with N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid to pH 7.4 at 37 degrees C. With fast perfusion, we found no evidence of decreased pH1, even with stimulation by 10 microM carbachol. With slow perfusion, pH1 often fell below the dye's sensitive range (pH < 5), especially at low perfusate buffering power. In other experiments, we loaded cells with the pH-sensitive dye 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein and monitored intracellular pH (pHi) in multiple individual PCs and CCs in a single gland. Mean pHi was 7.21 +/- 0.02 (n = 136 cells) for PCs and 7.27 +/- 0.03 (n = 103) for CCs. To examine the response to decreased pH1 and basolateral pH (pHb), we lowered pHb to 6.4 or lowered pH1 to 3.4 or 1.4. Lowering pHb to 6.4 for approximately 1 min caused pHi to fall reversibly by 0.39 +/- 0.05 (n = 53) in PCs and 0.58 +/- 0.03 (n = 50) in CCs. Lowering pH1 to 3.4 or 1.4 caused no significant pHi changes in PCs (n = 38 and 82) or in CCs (n = 44 and 77). Carbachol did not affect the response to changes in pH1 or pHb. We conclude that the apical surfaces of PCs and CCs are unusually resistant to extreme pH gradients.

scholarly journals Theoretical Comparison of McKibben-Type Artificial Muscle and Novel Straight-Fiber-Type Artificial Muscle

2011 ◽  
Vol 5 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Hiroki Tomori ◽  
◽  
Taro Nakamura
Keyword(s):  
Steady State ◽  
Dynamic Characteristic ◽  
Fiber Type ◽  
Human Life ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Contraction Rate ◽  
Theoretical Comparison ◽  
Straight Fiber ◽  
Force Characteristics

Robots have entered human life, and closer relationships are being formed between humans and robots. It is desirable that these robots be flexible and lightweight. With this as our goal, we have developed an artificial muscle actuator using straight-fiber-type artificial muscles derived from the McKibben-type muscles, which have excellent contraction rate and force characteristics. In this study, we compared the steady state and dynamic characteristic of straightfiber-type and McKibben-type muscles and verified the usefulness of straight-fiber-type muscles.

scholarly journals Phase transformation-driven artificial muscle mimics the multifunctionality of avian wing muscle

2021 ◽  
Vol 18 (184) ◽  
Author(s):  
Pedro B. C. Leal ◽  
Marcela Cabral-Seanez ◽  
Vikram B. Baliga ◽  
Douglas L. Altshuler ◽  
Darren J. Hartl
Keyword(s):  
Skeletal Muscle ◽  
Mechanical Performance ◽  
Dynamic Control ◽  
Artificial Muscle ◽  
Bipedal Walking ◽  
Artificial Muscles ◽  
Operational Conditions ◽  
Leg Muscles ◽  
Engineered Systems ◽  
Electrical Stimuli

Skeletal muscle provides a compact solution for performing multiple tasks under diverse operational conditions, a capability lacking in many current engineered systems. Here, we evaluate if shape memory alloy (SMA) components can serve as artificial muscles with tunable mechanical performance. We experimentally impose cyclic stimuli, electric and mechanical, to an SMA wire and demonstrate that this material can mimic the response of the avian humerotriceps, a skeletal muscle that acts in the dynamic control of wing shapes. We next numerically evaluate the feasibility of using SMA springs as artificial leg muscles for a bipedal walking robot. Altering the phase offset between mechanical and electrical stimuli was sufficient for both synthetic and natural muscle to shift between actuation, braking and spring-like behaviour.

Tensile and torsional elastomer fiber artificial muscle by entropic elasticity with thermo-piezoresistive sensing of strain and rotation by a single electric signal

2020 ◽  
Vol 7 (12) ◽  
pp. 3305-3315
Author(s):  
Run Wang ◽  
Yanan Shen ◽  
Dong Qian ◽  
Jinkun Sun ◽  
Xiang Zhou ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Natural Rubber ◽  
Artificial Muscle ◽  
Electric Signal ◽  
Artificial Muscles ◽  
Resistance Change ◽  
Entropic Elasticity

Artificial muscles are developed by using twisted natural rubber fiber coated with buckled carbon nanotube sheet, which show tensile and torsional actuations and sensing function via the resistance change by a single electric signal.

scholarly journals Design and Control of a 1-DOF Robotic Lower-Limb System Driven by Novel Single Pneumatic Artificial Muscle

2019 ◽  
Vol 10 (1) ◽  
pp. 43 ◽  
Author(s):  
Tsung-Chin Tsai ◽  
Mao-Hsiung Chiang
Keyword(s):  
Lower Limb ◽  
Artificial Muscle ◽  
Robotic System ◽  
Artificial Muscles ◽  
Prototype System ◽  
Pneumatic Artificial Muscle ◽  
Torsion Spring ◽  
Pneumatic Artificial Muscles ◽  
Control Response ◽  
Spring Mechanism

This study determines the practicality and feasibility of the application of pneumatic artificial muscles (PAMs) in a pneumatic therapy robotic system. The novel mechanism consists of a single actuated pneumatic artificial muscle (single-PAM) robotic lower limb that is driven by only one PAM combined with a torsion spring. Unlike most of previous studies, which used dual-actuated pneumatic artificial muscles (dual-PAMs) to drive joints, this design aims to develop a novel single-PAM for a one degree-of-freedom (1-DOF) robotic lower-limb system with the advantage of a mechanism for developing a multi-axial therapy robotic system. The lower limb robotic assisting system uses the stretching/contraction characteristics of a single-PAM and the torsion spring designed by the mechanism to realize joint position control. The joint is driven by a single-PAM controlled by a proportional pressure valve, a designed 1-DOF lower-limb robotic system, and an experimental prototype system similar to human lower limbs are established. However, the non-linear behavior, high hysteresis, low damping and time-variant characteristics for a PAM with a torsion spring still limits its controllability. In order to control the system, a fuzzy sliding mode controller (FSMC) is used to control the path tracking for the PAM for the first time. This control method prevents approximation errors, disturbances, un-modeled dynamics and ensures positioning performance for the whole system. Consequently, from the various experimental results, the control response designed by the joint torsion spring mechanism can also obtain the control response like the design of the double-PAMs mechanism, which proves that the innovative single-PAM with torsion spring mechanism design in this study can reduce the size of the overall aid mechanism and reduce the manufacturing cost, can also improve the portability and convenience required for the wearable accessory, and is more suitable for the portable rehabilitation aid system architecture.

Contractile Pneumatic Artificial Muscle Configured to Generate Extension

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Benjamin K. S. Woods ◽  
Shane M. Boyer ◽  
Erica G. Hocking ◽  
Norman M. Wereley ◽  
Curt S. Kothera
Keyword(s):  
Compressive Loading ◽  
Compressive Force ◽  
Artificial Muscle ◽  
Specific Power ◽  
Artificial Muscles ◽  
Specific Work ◽  
Operational Characteristics ◽  
Pneumatic Artificial Muscles ◽  
High Specific Power ◽  
Internal Mechanism

Pneumatic artificial muscles (PAMs) are comprised of an elastomeric bladder surrounded by a braided mesh sleeve. When the bladder is inflated, the actuator may either contract or extend axially, with the direction of motion dependent on the orientation of the fibers in the braided sleeve. Contractile PAMs have excellent actuation characteristics, including high specific power, specific work, and power density. Unfortunately, extensile PAMs exhibit much reduced blocked force, and are prone to buckling under axial compressive loading. For applications in which extensile motion and compressive force are desired, the push-PAM actuator introduced here exploits the operational characteristics of a contractile PAM, but changes the direction of motion and force by employing a simple internal mechanism using no gears or pulleys. Quasi-static behavior of the push-PAM was compared to a contractile PAM for a range of operating pressures. Based on these data, the push-PAM actuator can achieve force and stroke comparable to a contractile PAM tested under the same conditions.

Wearable Power Assist Device for Standing Up Motion Using Pneumatic Rubber Artificial Muscles

2007 ◽  
Vol 19 (6) ◽  
pp. 619-628 ◽  
Author(s):  
Toshiro Noritsugu ◽  
◽  
Daisuke Sasaki ◽  
Masafumi Kameda ◽  
Atsushi Fukunaga ◽  
...  
Keyword(s):  
Elderly Population ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
User Friendliness ◽  
Assist Device ◽  
Birth Rates ◽  
Standing Up ◽  
Basic Features ◽  
User Friendly ◽  
And Control

As society ages and birth rates fall, the dropping number of caregivers for an increasingly elderly population is expected to become a serious problem, raising the need for devices to assist those having difficulty in leading independent lives. These devices must be used near or directly on their users, making safety and user-friendliness equally important. This raises the need for safe, user-friendly actuators that are compact, lightweight, and appropriately soft. The pneumatic rubber artificial muscle meets this requirement. We developed a wearable power assist device that aids people in standing and uses the McKibben pneumatic rubber artificial muscle. We discuss its structure, basic features, and control. We also present an example of its application to rehabilitation.

POSITION AND VIBRATION CONTROL OF VARIABLE RHEOLOGICAL JOINTS USING ARTIFICIAL MUSCLES AND MAGNETO-RHEOLOGICAL BRAKE

2011 ◽  
Vol 08 (01) ◽  
pp. 205-222 ◽  
Author(s):  
TARO NAKAMURA ◽  
YUICHIRO MIDORIKAWA ◽  
HIROKI TOMORI
Keyword(s):  
Vibration Control ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Slow Response ◽  
Mr Fluid ◽  
Instantaneous Power ◽  
Human Contact ◽  
Joint Mechanism ◽  
Magneto Rheological ◽  
Mr Effect

In recent times, the chances of robot–human contact have increased; hence, safety is necessitated with regard to such contact. Thus, manipulators using a pneumatic rubber artificial muscle, which is lightweight and flexible, are studied. However, this artificial muscle manipulator has faults such as slow response and limited instantaneous power due to operation by air pressure. Because of these faults, uncontrollable vibrations can occur, leading to instability in the arm when an object is held and lifted. In this study, an artificial muscle manipulator with one DOF and a variable rheological joint mechanism using MR fluid is developed. Vibration control of the arm using MR fluid is realized when an object is held and lifted, confirming the reduction in vibration due to the MR effect.

Mechanism and Bias Considerations for Design of a Bi-Directional Artificial Muscle Actuator

2012 ◽  
Author(s):  
Robert D. Vocke ◽  
Curt S. Kothera ◽  
Norman M. Wereley
Keyword(s):  
Artificial Muscle ◽  
Design Parameters ◽  
Artificial Muscles ◽  
Baseline Design ◽  
Aerospace Applications ◽  
Arbitrary Loading ◽  
Mckibben Actuators ◽  
Improved Design ◽  
Kinematic Mechanism ◽  
Selection Of

Pneumatic artificial muscles (PAMs), or McKibben actuators, have received considerable attention for robotic manipulators and in aerospace applications due to their similarity to natural muscles. Like natural muscles, PAMs are a purely contractile actuator, so that, in order to produce bidirectional or rotational motion, they must be arranged in an agonist/antagonist pair, which inherently limits the deflection of the system due to the high parasitic stiffness of the antagonistic PAM. This study presents two methods for increasing the performance of an antagonistic PAM system by decreasing the passive parasitic moment, rather than increasing the active moment. The first involves selection of the kinematic mechanism geometry, and the second involves the introduction of bias into the system, both in terms of PAM contraction, and passive (antagonistic) PAM pressure. It was found with the proper selection of design parameters, including mechanism geometry, PAM geometry, and bias conditions, that an ideal actuator configuration can be found that maximizes deflection for a given arbitrary loading. When comparing a baseline design to an improved design for a simplified case, a nearly 50% increase in maximum deflection was predicted simply by optimizing mechanism geometry and bias contraction.

Developing a Novel Robotic Fish With Antagonistic Artificial Muscle Actuators

2017 ◽  
Author(s):  
Sunil Kumar Rajendran ◽  
Feitian Zhang
Keyword(s):  
Heat Dissipation ◽  
Weight Ratio ◽  
Artificial Muscle ◽  
Robotic Fish ◽  
Artificial Muscles ◽  
Underwater Robotics ◽  
Closed Loop System ◽  
Underwater Robots ◽  
Muscle Actuators ◽  
Novel Design

Super-coiled polymer (SCP), one of the newly-developed artificial muscles, has various advantages over traditional artificial muscles in terms of cost, flexibility and power-to-weight ratio. This paper investigates the performance of super-coiled polymer-based actuation in underwater robotics, and presents a novel design of robotic fish using antagonistic SCP actuators. Dynamic model of the robot is derived. An example robotic fish prototype is developed and used in experiments to study SCP actuation for underwater robots. Furthermore, experimental results show that using SCP actuators in robotic fish solves the challenging heat-dissipation problem at ease, thus improving the dynamic response of SCP actuation significantly. A PID controller is designed to regulate the tail flap angle of the designed robotic fish. Simulation results of the closed-loop system are presented to validate the proposed robot design and actuation approach.

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