New dielectric elastomers have been created by experts at the John A. Paulson school of Engineering and Applied Sciences at Harvard University. This creation can function with low voltage, gives a better range of motion for soft robots and does not require hard parts.
Soft robots are capable of carrying out a number of functions although they are quite slow. Actuators, which are the muscle for soft robots usually, make use of pneumatics or hydraulics. Dielectric elastomers carry some of the important features required for this such as good insulation, and soft matter although they are short of high voltage capability. Also contain rigid parts which are necessary for it to retain its shape and form.
These Elastomers make use of inefficient and very complicated circuitry to provide high voltage but without the rigid parts, they won’t keep their form.
Mishu Duduta, a graduate student from Havard who also doubles as the first author of the study said that this soft robotic innovation could be the trailblazer in the world of soft robotics. The studies carried out attempts to proffer solutions for the challenges of soft actuation. Actuation voltage is reduced while the energy density increases hence the hard elements are removed. She went further to say that until now, the soft robot actuator required electrical fields that were too high.
The team of experts made use of two different materials in building the dielectric elastomer including carbon nanotubes electrodes that had already been formed within the Clarke Lab. The second one was an elastomer that is based upon one that had already been formed at UCLA and this one didn’t need hard components for its operation.
When the two materials were utilised together, they seemed to work together just fine and as such the device was able to function better than other dielectric actuators. Most elastomers need to be pre-stretched before they can be joined to a rigid frame and hence offer only limited locomotion range. The UCLA-developed elastomer started as a fluid which was put underneath ultraviolet light to cure and no pre-stretching was needed.
This process produced sheets having two sticky sides that were quite thin hence they couldn’t comply well to the electrodes and with themselves. The nanotubes composed of carbon replaced the normally used carbon grease as the electrode. When these nanotubes are utilised, the energy density does not go higher and the elastomer density does not decrease. what this means is that significant force is still manufactured since the elastomer is still able to stretch.
The experts combined a multilayer of elastomers and electrodes so that one electrode could charge both the elastomer above and below it. It is very important to make a dielectric elastomer to be very thin since thicker materials require higher voltage, however, it mustn’t be too thin either.
The potential of the actuator is without limits because it can be used for a number of devices such as robotic muscles, soft robots, laparoscopic tools or soft grippers.