Technical Brief

Flexible Mechanical Joint as Human Exoskeleton Using Low-Melting-Point Alloy

[+] Author and Article Information
Yueguang Deng

Department of Biomedical Engineering,
School of Medicine,
Tsinghua University,
Beijing 100084, China

Jing Liu

Department of Biomedical Engineering,
School of Medicine,
Tsinghua University,
Beijing 100084, China;
Beijing Key Lab of Cryo-Biomedical Engineering
and Key Lab of Cryogenics,
Technical Institute of Physics and Chemistry,
Chinese Academy of Sciences,
Beijing 100190, China
e-mail: jliubme@tsinghua.edu.cn

1Corresponding author.

Manuscript received April 12, 2014; final manuscript received August 5, 2014; published online September 1, 2014. Assoc. Editor: Rita M. Patterson.

J. Med. Devices 8(4), 044506 (Sep 01, 2014) (3 pages) Paper No: MED-14-1169; doi: 10.1115/1.4028307 History: Received April 12, 2014; Revised August 05, 2014

A flexible mechanical joint for human exoskeleton based on low-melting-point alloy is proposed for the first time. With the liquid–solid phase change capability, this unique joint can easily switch between its flexible and rigid states. Such mechanism allows the fabricated human exoskeleton arm to conveniently and effectively perform the powerful lifting action. Conceptual investigations disclosed that metal-based mechanical joints provided excellent moving flexibility and large loading capacity. Comparative measurements demonstrated that the phase change joint responded much faster and could support heavier loads than that of the conventional paraffin-based joint. This method opens a soft mechanical joint for human exoskeleton in future civilian use.

Copyright © 2014 by ASME
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Grahic Jump Location
Fig. 1

Comparison of the (a) thermal conductivity and (b) latent heat between paraffin and a low-melting-point alloy

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Fig. 2

Prototype of flexible mechanical joint based on a low-melting-point alloy

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Fig. 3

Thermal behaviors of Bi32.5In51Sn16.5 in a mechanical joint under heating or freezing. (a) Typical temperature curve during melting; (b) typical temperature curve during freezing; (c) melting times under different heating powers; and (d) freezing times under different cooling powers.

Grahic Jump Location
Fig. 4

Comparison of mechanical strength between the low-melting-point alloy mechanical joint and that based on conventional paraffin



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