An international team led by researchers at Waterloo Engineering has found a way to dramatically strengthen smart, rubber-like materials to replace rigid motors and pumps in robots with flexible “artificial muscles.”
Soft robots differ from hard robots in that they are pliable and flexible, making them safe for interaction with people, but the materials now used for components enabling their movement aren’t strong enough to be effective.
“What we call artificial muscles are essential for unlocking the true potential of soft robots,” said Dr. Hamed Shahsavan, a professor of chemical engineering. “They allow robots to move flexibly, safely, and with precision. This is especially important for applications like micro-medical robots.”
A research group led by Shahsavan mixed liquid crystals (LCs) - which are commonly found in displays for electronics and sensors - into promising building blocks for soft robots known as liquid crystal elastomers (LCEs).
LCEs are rubbers that undergo massive shape change, in a reversible and programmable manner, when they are heated. Researchers discovered that mixing small amounts of LCs with LCEs made them much stiffer and up to nine times stronger.
“To put this in perspective, fibres from the new LCEs can, when heated, lift loads up to 2,000 times their own weight,” said Shahsavan, director of the Smart Materials for Advanced Robotic Technologies (SMART) Lab. “These LCEs provide output work of almost 24 J/kg, about three times more than the average work provided by the muscles of mammals.”
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