A large stroke, high force paraffin phase transition actuator

Klintberg, Lena; Karlsson, Mikael; Stenmark, Lars; Schweitz, Jan‐Åke; Thornell, Greger

doi:10.1016/s0924-4247(01)00785-3

Cited by 60 publications

(33 citation statements)

References 4 publications

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“…Torsional actuation at an average 11,500 revolutions per minute results from Joule heating of a paraffin wax-filled, twist-spun CNT yarn 3 . Paraffin is a wellknown thermal actuator material [7][8][9] in which the solid-liquid phase transition and thermal expansion provide B30% volume expansion. When confined within the pore space between twistspun CNT bundles, the wax volume increase drives a shortening and untwist of the host yarn that can be harnessed as tensile and torsional actuation, respectively.…”

mentioning

confidence: 99%

Hybrid carbon nanotube yarn artificial muscle inspired by spider dragline silk

et al. 2014

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Torsional artificial muscles generating fast, large-angle rotation have been recently demonstrated, which exploit the helical configuration of twist-spun carbon nanotube yarns. These wax-infiltrated, electrothermally powered artificial muscles are torsionally underdamped, thereby experiencing dynamic oscillations that complicate positional control. Here, using the strategy spiders deploy to eliminate uncontrolled spinning at the end of dragline silk, we have developed ultrafast hybrid carbon nanotube yarn muscles that generated a 9,800 r.p.m. rotation without noticeable oscillation. A high-loss viscoelastic material, comprising paraffin wax and polystyrene-poly(ethylene-butylene)-polystyrene copolymer, was used as yarn guest to give an overdamped dynamic response. Using more than 10-fold decrease in mechanical stabilization time, compared with previous nanotube yarn torsional muscles, dynamic mirror positioning that is both fast and accurate is demonstrated. Scalability to provide constant volumetric torsional work capacity is demonstrated over a 10-fold change in yarn cross-sectional area, which is important for upscaled applications.

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confidence: 99%

Hybrid carbon nanotube yarn artificial muscle inspired by spider dragline silk

et al. 2014

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“…It should be mentioned that the selection of materials, and the experimental conditions, were to some extent governed by the use of paraffin actuators in space applications [2,3]. The small dimensions of the samples primarily serve the purpose of getting as many samples as possible out of a silicon wafer.…”

Section: Discussionmentioning

confidence: 99%

A solder sealing method for paraffin-filled microcavities

Nguyen¹,

Bejhed²,

Köhler³

et al. 2006

J. Micromech. Microeng.

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Abstract.Demonstrated and investigated here is a method to seal microfluidic systems by soldering. As a particularly difficult case of growing importance, the sealing of openings contaminated with paraffin wax was studied. Solder paste, screen printed on a metallized silicon, substrate was melted locally through application of 6.5 to 10 V to a 5 Ω copper film resistor for a few seconds and found able to drive an intermediate layer of paraffin away and seal a 0.2 mm diameter circular via by wetting to a surrounding copper pad. Although verified to be robust, the process did result in failing seals on excessive heating because of consumption of the pads. Correctly performed, the technique provided a seal at least withstanding a pressure of 8 bar for 8 h at 85ºC.

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“…The concept is built on the principle that an enclosed cavity is filled with an essentially incompressible material [2]. The enclosed material increases in volume as it changes phase.…”

Section: Flow Control Valvesmentioning

confidence: 99%