In a new development, material scientists at UCLA and their colleagues at non-profit SRI International have developed a new material and manufacturing process for the fabrication of artificial muscles that surpass biological muscles for strength and flexibility.
The fabrication of artificial muscle to work and detect touch and force has been a key challenges of science and engineering, stated one of the associates behind the material.
In fact, to consider a soft material for use as artificial muscle, it must be able to release mechanical energy and remain usable under high-strain conditions. This means the material does not lose form and strength easily after repeated work cycles.
Whilst a number of materials have been considered for creating artificial muscles, dielectric elastomers have drawn attention because of their optimal flexibility and solid toughness.
Function-wise, dielectric elastomers are synthetic or natural substances made of large molecules that can change in shape or size when stimulated by an electric field. Dielectric elastomers can be used as actuators that enable machines to work by transforming electric energy into mechanical work.
Meanwhile, most dielectric elastomers are composed of either silicone or acrylic. Nonetheless both materials have shortcomings. While traditional acrylic dielectric elastomers can attain high actuation strain, it has shortcomings of pre-stretching and lack of flexibility.
On the other hand, silicones are easier to make, but they are unable to withstand high strain.
With the utilization of commercially available chemicals and employing an ultraviolet light curing process, the research team developed an improved acrylic-based material that is more tunable, pliable, and simpler to scale without losing it endurance and strength. While the acrylic acid allows increased number of hydrogen bonds, it enables the elastomer to be softer and more flexible.