A new technology for artificial muscles could be a boon to medical device manufacturers, according to a recently published paper in the Journal of Advanced Materials. The paper, dubbed Powerful, Multifunctional Torsional Micro Muscles Activated by Phase Transition, explores how vanadium dioxide can significantly boost the strength of these artificial muscles.
Vanadium oxide is an inorganic, amphoteric compound. At room temperature, this compound features a distorted type of structure. When the compound is raised above 68°C, a break in the metal-metal bonds in the compound help cause an increase in electrical conductivity. This transition gives the metal a significant amount of strength. Researchers estimate that the artificial muscles manufactured with this compound have a strength that is 1000 times greater than regular human muscles.
"With its combination of power and multi-functionality, our micro-muscle shows great potential for applications that require a high level of functionality integration in a small space," stated Junqiao Wu, a professor at UC Berkeley who helped develop the new artificial muscles. "Multiple micro-muscles can be assembled into a micro-robotic system that simulates an active neuromuscular system."
While the artificial muscle operates at a temperature that is higher than the normal human body, this type of artificial muscle could be beneficial for prosthetics and other medical devices that operate outside the body. If properly insulated, the technology could potentially be used in some implantable medical devices.
Since the artificial muscle has a strength that is much greater than natural human muscles, it may be possible to use miniature artificial muscles to power implantable medical devices. Small artificial muscles are not likely to generate as much heat as larger ones.
A vanadium dioxide-based micromuscle can be used to throw an object in a micro-catapult mode. After this, researchers showed they could regear the artificial muscle in micro-explosion mode. In this mode, the artificial muscle can sense objects and respond to them with force.
The artificial muscle can be heated through a variety of different techniques. These include heating pads and an induced electric current. Alternatively, directed light pulses can also be used to activate the vanadium dioxide in the artificial muscle.
As of now, the technology for this artificial muscle is still under development. However, growing numbers of medical devices are utilizing non-rotary systems to generate force. For example, some modern artificial hearts don't feature a constant-force rotary pump. Instead, they mimic the natural pumping motion of the human heart. As artificial muscles continue to advance, future iterations of this technology and others could revolutionize medical devices.
