Liquid crystals boosts strength of elastomeric robotic “muscles”

Waterloo, Canada – Researchers at the University of Waterloo have developed a new elastomeric material that could improve the performance of soft robots by making flexible artificial muscles significantly stronger.

Soft robots use pliable components instead of rigid motors, but existing materials that enable movement often lack the strength needed for practical use.

The research team found that adding small amounts of liquid crystals to liquid crystal elastomer (LCEs), can stiffen the material and make it up to nine times stronger, said a 23 Oct report by the university.

LCEs are considered as ‘building blocks’ for soft robots as they undergo large, reversible shape changes when heated.

According to the research team, the liquid crystals disperse throughout the LCE and form small internal pockets, which behave like solids and reinforce the surrounding material.

“What we call artificial muscles are essential for unlocking the true potential of soft robots,” said Dr Hamed Shahsavan, lead researcher and a professor of chemical engineering at Waterloo.

“They allow robots to move flexibly, safely, and with precision. This is especially important for applications like micro-medical robots.”

The newly developed material, Shahsavan said, ‘dramatically strengthens’ elastomers while preserving their ability to move and reshape.

In testing, fibres made from the new material were able to lift loads up to 2,000 times their own weight when heated, the researchers reported.

The material also delivered output work of almost 24J/kg, around three times the average output of mammalian muscle.

The researchers expect LCEs with improved mechanical properties to play a significant role in the emerging field of soft robotics by “enabling extremely wide ranges of motion and powerful movements.”

The muscles, they expect, can be used in a range of applications, including drug delivery as well as in robots used in manufacturing plants.

“Materials with such capabilities are highly desired in robotics as they can replace old-school, bulky, heavy actuators and electromotors with light, soft, artificial muscles without sacrificing performance,” Shahsavan said.

The team is now working to adapt the reinforced LCEs for use as 3D-printing inks, a step intended to simplify manufacturing of custom robotic parts.