TY - JOUR
T1 - Dynamically Tunable Friction via Subsurface Stiffness Modulation
AU - Sharifi, Siavash
AU - Rux, Caleb
AU - Sparling, Nathaniel
AU - Wan, Guangchao
AU - Mohammadi Nasab, Amir
AU - Siddaiah, Arpith
AU - Menezes, Pradeep
AU - Zhang, Teng
AU - Shan, Wanliang
N1 - Publisher Copyright:
© Copyright © 2021 Sharifi, Rux, Sparling, Wan, Mohammadi Nasab, Siddaiah, Menezes, Zhang and Shan.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - Currently soft robots primarily rely on pneumatics and geometrical asymmetry to achieve locomotion, which limits their working range, versatility, and other untethered functionalities. In this paper, we introduce a novel approach to achieve locomotion for soft robots through dynamically tunable friction to address these challenges, which is achieved by subsurface stiffness modulation (SSM) of a stimuli-responsive component within composite structures. To demonstrate this, we design and fabricate an elastomeric pad made of polydimethylsiloxane (PDMS), which is embedded with a spiral channel filled with a low melting point alloy (LMPA). Once the LMPA strip is melted upon Joule heating, the compliance of the composite structure increases and the friction between the composite surface and the opposing surface increases. A series of experiments and finite element analysis (FEA) have been performed to characterize the frictional behavior of these composite pads and elucidate the underlying physics dominating the tunable friction. We also demonstrate that when these composite structures are properly integrated into soft crawling robots inspired by inchworms and earthworms, the differences in friction of the two ends of these robots through SSM can potentially be used to generate translational locomotion for untethered crawling robots.
AB - Currently soft robots primarily rely on pneumatics and geometrical asymmetry to achieve locomotion, which limits their working range, versatility, and other untethered functionalities. In this paper, we introduce a novel approach to achieve locomotion for soft robots through dynamically tunable friction to address these challenges, which is achieved by subsurface stiffness modulation (SSM) of a stimuli-responsive component within composite structures. To demonstrate this, we design and fabricate an elastomeric pad made of polydimethylsiloxane (PDMS), which is embedded with a spiral channel filled with a low melting point alloy (LMPA). Once the LMPA strip is melted upon Joule heating, the compliance of the composite structure increases and the friction between the composite surface and the opposing surface increases. A series of experiments and finite element analysis (FEA) have been performed to characterize the frictional behavior of these composite pads and elucidate the underlying physics dominating the tunable friction. We also demonstrate that when these composite structures are properly integrated into soft crawling robots inspired by inchworms and earthworms, the differences in friction of the two ends of these robots through SSM can potentially be used to generate translational locomotion for untethered crawling robots.
KW - dynamically tunable friction
KW - low melting point alloy
KW - soft robots
KW - subsurface stiffness modulation
KW - untethered crawling robots
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U2 - 10.3389/frobt.2021.691789
DO - 10.3389/frobt.2021.691789
M3 - Article
AN - SCOPUS:85110399905
SN - 2296-9144
VL - 8
JO - Frontiers in Robotics and AI
JF - Frontiers in Robotics and AI
M1 - 691789
ER -