Actuators, the artificial muscles for soft robots, usually use pneumatics or hydraulics.
There is a solution for this in the form of dielectric elastomers.
Dielectric elastomers have some of the essential qualities necessary for this use including good insulation and soft materials, but they lack the ability to provide high voltage and rigid components so that their form can be maintained.
A new dielectric elastomer has been developed by researchers at the John A. Paulson School of Engineering and Applied Sciences at Harvard that can work with low-voltage, offers a better range of motion and doesn’t require rigid components.
A graduate student from the school and the first author of the study paper named Mishu Duduta says that this soft robotic could potentially be the Holy Grail for soft robotics.
The research that has been carried out offers solutions for the issues with soft actuation.
The team of researchers used two different materials to build the dielectric elastomer including a carbon nanotubes electrode that had been developed already in the Clarke Lab.
When these two materials were used together, they complemented each other perfectly and as a result, the new device was able to outperform other dielectric elastomer actuators.
Most elastomers have to be pre-stretched before they can be attached to a rigid frame and thus offer only a limited motion range.
Thin nanotubes made of carbon replaced the commonly used carbon grease as the electrode.
When these nanotubes are used the energy density does not decrease, and the elastomer stiffness does not increase.
The research team put together a multilayer of elastomers and electrodes so that one electrode could power both the elastomer above it and below it.
According to Duduta, it’s important to make a dielectric elastomer fragile since the thicker the material, the more voltage is required.
If the elastomer is too thin, it won’t be able to produce enough force and will be flimsy.
She goes on to say that this research has been particularly significant due to the combining of the materials and their processing to overcome the current limitations of pre-stretching and high-voltage use.
The potential for this actuator is quite limitless since it could be utilized for a variety of devices including complex robotic artificial muscles, soft robots, laparoscopic tools or elastic grippers.