RT Journal Article
SR Electronic
T1 Actuation of untethered pneumatic artificial muscles and soft robots using magnetically induced liquid-to-gas phase transitions
JF Science Robotics
JO Sci. Robotics
FD American Association for the Advancement of Science
SP eaaz4239
DO 10.1126/scirobotics.aaz4239
VO 5
IS 41
A1 Mirvakili, Seyed M.
A1 Sim, Douglas
A1 Hunter, Ian W.
A1 Langer, Robert
YR 2020
UL http://robotics.sciencemag.org/content/5/41/eaaz4239.abstract
AB Pneumatic artificial muscles have been widely used in industry because of their simple and relatively high-performance design. The emerging field of soft robotics has also been using pneumatic actuation mechanisms since its formation. However, these actuators/soft robots often require bulky peripheral components to operate. Here, we report a simple mechanism and design for actuating pneumatic artificial muscles and soft robotic grippers without the use of compressors, valves, or pressurized gas tanks. The actuation mechanism involves a magnetically induced liquid-to-gas phase transition of a liquid that assists the formation of pressure inside the artificial muscle. The volumetric expansion in the liquid-to-gas phase transition develops sufficient pressure inside the muscle for mechanical operations. We integrated this actuation mechanism into a McKibben-type artificial muscle and soft robotic arms. The untethered McKibben artificial muscle generated actuation strains of up to 20% (in 10 seconds) with associated work density of 40 kilojoules/meter3, which favorably compares with the peak strain and peak energy density of skeletal muscle. The untethered soft robotic arms demonstrated lifting objects with an input energy supply from only two Li-ion batteries.