Tiny But Mighty, Bug-Like Microrobots Are Gaining Strength
With a new kind of artificial muscle, a team at MIT can build diminutive drones that zip around with a bug-like agility and resilience.
“This opens up a lot of opportunity in the future for us to transition to putting power electronics on the microrobot," says senior author of the paper, Kevin Chen .
Transcript
00:00:00 [MUSIC PLAYING] MIT researchers have developed a new fabrication technique that enables them to produce low-voltage, power-dense, high-endurance soft actuators for an aerial microrobot. These artificial muscles vastly improve the robot's payload and allow it to hover for 20 seconds, which is the longest ever recorded
00:00:20 by a robot of its size. The rectangular microrobot, which weighs less than one-fourth of a penny, has four sets of wings that are each driven by a soft actuator. These muscle-like actuators are made from layers of elastomer that are sandwiched between two very thin electrodes and then rolled into a squishy cylinder.
00:00:39 When the voltage is applied to the actuator the electrodes squeeze the elastomer and that mechanical strain is used to flap the wing. This new fabrication technique produces artificial muscles with fewer defects, which dramatically extends the life-span of its components and increases the robots performance and payload.
00:00:59 The more surface area the actuator has the less voltage is required, so the researchers built these artificial muscles by alternating between as many, ultra-thin layers of elastomer and electrode as they could. They were able to create an actuator with 20 layers each of which is ten micrometers in thickness; about the diameter of a red blood cell.
00:01:20 During the spin-coating process, an elastomer is poured onto a flat surface and rotated rapidly. The centrifugal force pulls the film outward to make it thinner. However, air comes back into the elastomer and creates a lot of microscopic air bubbles, which become stronger as the layers get thinner.
00:01:37 They found that if they perform a vacuuming process immediately after spin-coating, while the elastomer is still wet, it removes the air bubbles. Removing these defects increases the power output of the actuator by more than 300 percent and significantly improves its lifespan. Currently, the team is limited to how they can make the layers
00:01:57 due to dust in the air and a maximum spin-coating speed. They are planing to work in a clean room which will eliminate this problem and would allow them to use methods that are more precise. Ultimately, they hope to reduce the actuator layer from ten micrometers to only one micrometer, which would open the door to many applications for these
00:02:17 insect-sized robots.