[Image from the University of Hong Kong]
The new actuating material is made from nickel hydroxide-oxyhydroxides and is powered by visible light, electricity and other stimuli. The material actuation is triggered by visible light to create a fast deformation while also exerting a force of 3,000 times its own weight.
Light-induced actuating materials are desirable because they are often used to control robots wirelessly. However, there is a limited amount of light-driven materials available and the ones that are available are typically more expensive to produce, according to the researchers. The high production costs have prevented the materials from being used in actual applications like artificial muscles for robotics and human assist devices and minimally invasive surgical and diagnostic tools.
According to the researchers, material that is actuated by visible light can create strong, quick and stable actuation, which is what the nickel hydroxide-oxyhydroxides material is capable of doing. The material can be actuated by light at a low intensity to create high strand speed that is comparable to mammalian skeletal muscles.
The material is also able to be actuated by electricity that allows it to be used in different robotic technologies. It is also responsive to heat and humidity changes which enables it to be used in autonomous machines that use tiny energy changes in the environment.
Researchers tested the material using a mini arm made from two hinges of actuating materials. The “arm” was able to lift an object that was 50 times its weight.
By scaling up fabrication, the researchers suggest the material could create artificial muscles that are comparable to mammalian skeletal muscles. The material could then be applied in robotics, human assist devices and medical devices.
The cost of the material of a typical actuator is as low as 4 HKD ($0.51) per cm2, according to the researchers, and only takes around three hours to fabricate.
The research was led by professor Alfonso Ngan at the University of Hong Kong and was published in the journal Science Robotics.
