It would seem shape memory metal alloys are finding a unique role in enabling the development of Micro Aerial Vehicles (MAV’s) according to a report in Science Daily.
A number of projects are running around the country to develop the technology, and it’s not just for geek model makers, the number of uses is limited only by imagination as the military knows only too well. The US Air force is funding research at the University of Florida into 6-24 drones to use particularly in urban environments. The much larger surveillance and attack drones which have proved so popular with the military in Iraq and Afghanistan will shortly be joined by the micro versions capable of close quarter surveillance and equipped with sensors to sniff our chemical and biological weapons or eavesdrop on enemy positions.
In Cologne, Germany a quadrocopter developed by the Fraunhofer Institute for Information and Data Processing IITB in Karlsruhe has been used to search for survivors in a collapsed building. The team are working on software that would allow the mini quadrocopters to communicate with each other and operate autonomously. Researchers think they are just one year away from launching their first swarm.
The most fascinating project though is one run by researchers at the North Carolina State University; they looked at nature and decided the most maneuverable model would be a bat because of their extreme efficiency in negotiating tight spaces. They have analyzed the bats’ skeletal and muscular systems before developing a “robo-bat” skeleton using rapid prototyping technologies. The fully assembled skeleton rests easily in the palm of the hand and, weighs less than 6 grams (0.2 ounce). The research team is also using smart metals for the muscular system. “We’re using a metal alloy that responds to the heat from an electric current. That heat actuates micro-scale wires the size of a human hair, making them contract like ‘metal muscles.’ During the contraction, the powerful muscle wires also change their electric resistance, which can be easily measured, thus providing simultaneous action and sensory input. This dual functionality will help cut down on the robo-bat’s weight, and allow the robot to respond quickly to changing conditions ” such as a gust of wind ” as perfectly as a real bat.” The use of shape memory metal alloys allows the creation of super elastic joints. The material provides a full range of motion but always returns to its original position, just like tiny cartilages, bones and tendons do in real bats.
No doubt the military will be knocking on North Carolina state’s door as work progresses but hopefully the research work will also be of value in increasing our understanding of both aerodynamics and metal technologies.