Graphene/silver nanoflower hybrid coating for improved cycle performance of thermally-operated soft actuators

Abstract Twisted and coiled actuators (TCAs), fabricated by twisting cheap nylon sewing threads, have attracted a great deal of attention for their use as artificial muscles or soft actuators. Since the dynamic behavior of a thermally-operated TCA is governed by its thermal properties, graphene and silver nanoflowers (AgNFs) were spray-coated onto the surface of an actuator to achieve enhanced heat transfer. Addition of AgNFs improves interfacial thermal contacts between graphene flakes, while pristine graphene flakes have extremely high in-plane thermal conductivity. Thus, the synergistic effect of graphene and AgNFs reduced the total cycle time of the TCA by up to 38%. Furthermore, when a pulsed current with a 40% duty cycle was applied to the TCA, the graphene/AgNF-coated TCA exhibited a threefold larger peak-to-peak amplitude of the displacement oscillation of the actuator, as compared to that of the non-coated TCA, which demonstrates that the combination of graphene and AgNFs effectively reduced a cooling time of the TCA. This work shows great potential for a simple coating of graphene and AgNFs to produce high-performance thermally-operated soft actuators.

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Implementation of Soft-Lithography Techniques for Fabrication of Bio-Inspired Multi-Layer Dielectric Elastomer Actuators with Interdigitated Mechanically Compliant Electrodes

Actuators ◽

10.3390/act7040073 ◽

2018 ◽

Vol 7 (4) ◽

pp. 73 ◽

Cited By ~ 3

Author(s):

Mert Corbaci ◽

Wayne Walter ◽

Kathleen Lamkin-Kennard

Keyword(s):

Soft Lithography ◽

Skeletal Muscles ◽

Actuation Voltage ◽

Transition Process ◽

Humanoid Robots ◽

Dielectric Elastomer ◽

Industrial Robots ◽

Artificial Muscles ◽

Dielectric Elastomer Actuators ◽

Soft Actuators

Advancements in software engineering have enabled the robotics industry to transition from the use of giant industrial robots to more friendly humanoid robots. Soft robotics is one of the key elements needed to advance the transition process by providing a safer way for robots to interact with the environment. Electroactive polymers (EAPs) are one of the best candidate materials for the next generation of soft robotic actuators and artificial muscles. Lightweight dielectric elastomer actuators (DEAs) provide optimal properties such as high elasticity, rapid response rates, mechanical robustness and compliance. However, for DEAs to become widely used as artificial muscles or soft actuators, there are current limitations, such as high actuation voltage requirements, control of actuation direction, and scaling, that need to be addressed. The authors’ approach to overcome the drawbacks of conventional DEAs is inspired by the natural skeletal muscles. Instead of fabricating a large DEA device, smaller sub-units can be fabricated and bundled together to form larger actuators, similar to the way myofibrils form myocytes in skeletal muscles. The current study presents a novel fabrication approach, utilizing soft lithography and other microfabrication techniques, to allow fabrication of multilayer stacked DEA structures, composed of hundreds of micro-sized DEA units.

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A waste biomass derived hard carbon as a high-performance anode material for sodium-ion batteries

Journal of Materials Chemistry A ◽

10.1039/c6ta04877c ◽

2016 ◽

Vol 4 (34) ◽

pp. 13046-13052 ◽

Cited By ~ 138

Author(s):

Pin Liu ◽

Yunming Li ◽

Yong-Sheng Hu ◽

Hong Li ◽

Liquan Chen ◽

...

Keyword(s):

Anode Material ◽

High Performance ◽

Coulombic Efficiency ◽

Low Cost ◽

Sodium Ion ◽

Cycle Performance ◽

Sodium Ion Batteries ◽

Waste Biomass ◽

Hard Carbon ◽

Practical Applications

This study reports a hard carbon material derived from a waste biomass of corn cob and the influence of carbonized temperature on electrochemical performance. This study provides a promising anode material with low cost, high initial coulombic efficiency and excellent cycle performance, making sodium-ion batteries closer to practical applications.

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A novel green approach for the preparation of high performance nitrile butadiene rubber-pristine graphene nanocomposites

Composites Part B Engineering ◽

10.1016/j.compositesb.2019.107174 ◽

2019 ◽

Vol 175 ◽

pp. 107174 ◽

Cited By ~ 2

Author(s):

Bony Thomas ◽

Hanna J. Maria ◽

Gejo George ◽

Sabu Thomas ◽

N.V. Unnikrishnan ◽

...

Keyword(s):

High Performance ◽

Pristine Graphene ◽

Butadiene Rubber ◽

Graphene Nanocomposites ◽

Nitrile Butadiene Rubber ◽

Green Approach

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Fast Sheath-driven Electrothermal Artificial Muscles with High Power Densities

10.21203/rs.3.rs-1051698/v1 ◽

2021 ◽

Author(s):

Xinghao Hu ◽

Jingjing Jia ◽

Yingming Wang ◽

Xintian Tang ◽

Shaoli Fang ◽

...

Keyword(s):

Direct Contact ◽

High Performance ◽

Large Diameter ◽

Average Power ◽

Artificial Muscles ◽

Slow Cooling ◽

Prior Art ◽

Performance Results ◽

Power Densities ◽

Sheath Material

Abstract Electrothermal carbon nanotube (CNT) yarn muscles can provide large strokes during heating-cooling cycles. However, the slow cooling rate of thermal muscles limit their applications, since large diameter prior-art thermal muscles cannot be rapidly cycled. We here report an ultrafast thermally powered sheath-driven yarn muscle that uses a hybrid CNT sheath and an inexpensive polymer core. Our coiled muscle contracts 14.3% at 1 Hz and 7.3% at 8 Hz in air when powered by a square-wave electrical voltage input. The 70-mm-diameter actuated muscle cools in air to 16℃ from 150℃ within 0.5 s, compared with 6 s for a 65-mm-diameter sheath-run muscle that uses an electrothermally heated CNT core and 9 s for a 78-mm-diameter muscle that uses the sheath material for the entire muscle. An average power density of 12 kW/kg was obtained for a sheath-driven muscle, which is 42 times that for human skeletal muscle. This high performance results since the heating that drives fast actuation cycles is largely restricted to the muscle sheath, and this sheath is in direct contact with ambient temperature air.

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Fabrication of pristine graphene-based conductive polystyrene composites towards high performance and light-weight

Composites Science and Technology ◽

10.1016/j.compscitech.2018.02.013 ◽

2018 ◽

Vol 159 ◽

pp. 232-239 ◽

Cited By ~ 23

Author(s):

Fangwei Zhao ◽

Guangfa Zhang ◽

Shuai Zhao ◽

Jian Cui ◽

Ailin Gao ◽

...

Keyword(s):

High Performance ◽

Pristine Graphene ◽

Light Weight

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Study on walking training system by using both rubber artificial muscles and high-performance shoes with human compatibility

Journal of Biotechnology ◽

10.1016/j.jbiotec.2018.06.144 ◽

2018 ◽

Vol 280 ◽

pp. S45

Author(s):

Yasuhiro Hayakawa

Keyword(s):

High Performance ◽

Training System ◽

Artificial Muscles

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A high-performance Ce and Sn co-doped cathode material with enhanced cycle performance and suppressed voltage decay for lithium ion batteries

Ceramics International ◽

10.1016/j.ceramint.2019.07.064 ◽

2019 ◽

Vol 45 (16) ◽

pp. 20780-20787 ◽

Cited By ~ 2

Author(s):

Yanying Liu ◽

Ranran Li ◽

Jianling Li ◽

Zhe Yang ◽

Jianjian Zhong ◽

...

Keyword(s):

Cathode Material ◽

Lithium Ion Batteries ◽

High Performance ◽

Lithium Ion ◽

Cycle Performance ◽

Voltage Decay ◽

Co Doped

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Recent Advances in Graphene-Based Humidity Sensors

Nanomaterials ◽

10.3390/nano9030422 ◽

2019 ◽

Vol 9 (3) ◽

pp. 422 ◽

Cited By ~ 26

Author(s):

Chao Lv ◽

Cun Hu ◽

Junhong Luo ◽

Shuai Liu ◽

Yan Qiao ◽

...

Keyword(s):

Graphene Oxide ◽

High Performance ◽

Graphene Quantum Dots ◽

Pristine Graphene ◽

High Electron ◽

Humidity Sensors ◽

Industrial Processing ◽

Surface Areas ◽

Recent Advances ◽

Metal Metal

Humidity sensors are a common, but important type of sensors in our daily life and industrial processing. Graphene and graphene-based materials have shown great potential for detecting humidity due to their ultrahigh specific surface areas, extremely high electron mobility at room temperature, and low electrical noise due to the quality of its crystal lattice and its very high electrical conductivity. However, there are still no specific reviews on the progresses of graphene-based humidity sensors. This review focuses on the recent advances in graphene-based humidity sensors, starting from an introduction on the preparation and properties of graphene materials and the sensing mechanisms of seven types of commonly studied graphene-based humidity sensors, and mainly summarizes the recent advances in the preparation and performance of humidity sensors based on pristine graphene, graphene oxide, reduced graphene oxide, graphene quantum dots, and a wide variety of graphene based composite materials, including chemical modification, polymer, metal, metal oxide, and other 2D materials. The remaining challenges along with future trends in high-performance graphene-based humidity sensors are also discussed.

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