Double Helix Actuators

Shepherd, David; Spinks, Geoffrey M.

doi:10.1002/admt.201800525

Cited by 10 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is commonly accepted that the volume expansion is positively correlated with mass swelling. [ 33–36 ] However, if it is true here, the positive curvature will conflict with the conclusion (1). If it is false here, the final negative curvature and the results in Figure 3b cannot be explainable.…”

Section: Resultsmentioning

confidence: 80%

Bilayer Actuator with Overload Protection on the Basis of Semicrystalline Polyurethane

Zhang

Mao

Zheng

et al. 2023

Macromol. Rapid Commun.

View full text Add to dashboard Cite

Response to external stimuli plays a significant role in the environmental adaptation of living matters and intelligent devices. Most stimulus–response systems in nature can respond to appropriate stimuli, and inhibit the response under excessive stimuli, such as excessive heat or water, which can be called overload protection. However, even though various responsive materials have been developed for different stimuli, most of them are not protective against the overload stimuli. In this work, a bilayer actuator based on semicrystalline polyurethane is designed, which can respond differently to proper stimuli and excessive stimuli, i.e., water. This actuator can bend gradually under the proper stimulation of water, but will straighten and even bend reversely with excessive stimulation. The mechanism behind the reversible and adjustable actuator with overload protection is investigated both experimentally and theoretically, and the competition between dynamic factors and thermodynamic stability in the swelling process is considered the main cause.

show abstract

Section: Resultsmentioning

confidence: 80%

Bilayer Actuator with Overload Protection on the Basis of Semicrystalline Polyurethane

Zhang

Mao

Zheng

et al. 2023

Macromol. Rapid Commun.

View full text Add to dashboard Cite

show abstract

“…44,45 These novel active materials can respond to other stimuli than temperature, ranging from electric fields to light or can be chemically driven by swelling. 46,47 The presented method should be feasible to effectively process such torque-driven fiber-baser actuators but also bending-driven bilayer fibers. 48,49 Potentially suitable materials not only include pure or coated thermoplastic polymers but also particle-filled elastomers showing interesting sensing properties.…”

Section: Resultsmentioning

confidence: 99%

Continuous textile manufacturing method for twisted coiled polymer artificial muscles

Mersch

Witham

Solzbacher

et al. 2023

Textile Research Journal

View full text Add to dashboard Cite

Twisted, coiled polymer actuators (TCPAs) are a promising type of fiber-based actuators with high energy density, low material costs, and good recyclability; however, current manufacturing methods limit the length and stability of TCPAs, hampering their potential for large-scale textile applications. To overcome this limitation, we propose a textile manufacturing method based on the false-twisting principle, allowing for continuous and rapid production of highly twisted monofilaments. Additionally, this process enables the plying of two or more twisted monofilaments together, as well as the integration of wires for heating and sensing purposes. The resulting twist-stable plies can then be mandrel-coiled and annealed to create a new class of TCPAs with three superimposed levels of helicity, in contrast to the usual two levels. In this study, we investigate the impact of the additional helix level and various factors, including twist density, annealing temperature, cooling speed, and chirality, on the contractility of these TCPAs. Furthermore, due to the twist-stability of the plied yarns, they can be processed on standard textile machines, enabling the manufacture of TCPAs with multiple active yarns that can form contracting artificial muscles using a circular braiding machine. Our key findings reveal that the twisted monofilament coils can contract up to 60%, and higher twist density leads to improved performance for monofilament TCPAs. Notably, this phenomenon is not observed in plied-yarn TCPAs, where varying levels of twist on the monofilament and yarn helix level result in enhanced contractile performance. Overall, this work presents a novel textile manufacturing method for producing twist-stable TCPAs with good contractile performance, providing insights into the design and fabrication of advanced fiber-based actuators for potential applications in large-scale textiles, robotics, and biomedical devices.

show abstract

“…For example, the ability to output work allows these artificial muscles to be employed in the field of soft robotics, within robotic arms, and in prostheses. 7,72,97,[116][117][118][119][120][121][122][123][124][125][126][127] Actuation in response to body fluid may allow these artificial muscles to be used as sensors, controlled drug release devices, and medical catheters. [128][129][130][131][132][133][134][135][136][137][138] The ability to weave artificial muscle fibers into materials enables their use in smart textiles for thermal management systems.…”

Section: Applications Of Twisted-fiber Artificial Musclesmentioning

confidence: 99%