Developed new artificial muscles that allow insect robots to fly longer, more efficiently and with heavier loads, to perform tasks ranging from pollinating crops to rescuing people from disaster sites. The result, obtained by researchers from the Massachusetts Institute of Technology (MIT), is being published in the Advanced Materials journal.
“We have shown that these robots, which weigh less than a gram, fly longer than others with the least margin of error when hovering,” explains study coordinator Kevin Chen. The novelty lies in the ‘muscles’ of these insect-robots: they are soft actuators, made with layers of elastomer placed between two very thin electrodes and then rolled into a sort of soft cylinder.
When voltage is applied to the actuator, the electrodes squeeze the elastomer and the mechanical tension is used to flap the wing. The larger the actuator surface, the lower the voltage required: for this reason, the researchers developed an actuator made of 20 layers, each 10 thousandths of a millimeter thick (as thick as a red blood cell), reducing the required voltage by 75%. To further improve performance, they also optimized the electrodes, composed of carbon nanotubes.
In tests, the actuator required less than 500 volts to operate and produced enough energy to carry loads three times the weight of the robot. The mini-drones also successfully passed a 20-second long standing flight test, a record for those under one gram in weight. The actuator was still in excellent condition after 2 million cycles, far exceeding the life of the other actuators.
Source From: Ansa