MIT researchers reinvent the fabrication technique behind micro robots to operate at low voltage to enable them to carry more payload.
The power of micro robots is immense, right from pollinating drones to drones that locate buried survivors in the rubble. Size does not matter, the microrobots can bring humans to where they have never been.
Researchers from MIT have redefined and tested a highly technical fabrication technique. The new technique comprises soft actuators, elastomers, and voltage distributors which produces artificial muscles with fewer defects.
The small size makes the micro-robots featherweight and enables them to carry necessary power electronics that allow them to fly. The new fabrication technique will allow researchers to produce artificial muscles using soft actuators; it will enable them to flap the diminutive drone’s wings rapidly. The new studies suggest more surface area the actuator has the less voltage is required. Keeping this in mind they have created an actuator with 20 layers, each of which is 10 micrometers in thickness (about the diameter of a red blood cell).
The soft actuators developed by MIT researchers will operate with 75% low voltage and 80% more payload than the current versions. The power output of the actuator has also increased by more than 300% and the lifespan of the microbots has also significantly improved.
According to Kevin Chen, an assistant professor at MIT, “We demonstrate that this robot, weighing less than a gram, flies for the longest time with the smallest error during a hovering flight.”
In the video below you can see the design and construction process behind the development of microbots.
The MIT researchers said, “Each rectangular micro-robot…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. When the voltage is applied to the actuator, the electrodes squeeze the elastomer and that mechanical strain is used to flap the wings.”
The researchers have also optimized thin electrodes, which are composed of carbon nanotubes that help increase the actuator’s power output and reduce the voltage.
Prior to perfecting the concentrations, while working with the thin layer of elastomer the sharp ends of the carbon nanotubes would puncture it. While it takes a longer time to dry the layers added during the curing stage to the actuators.
Chen explained, “The first time I asked my student to make a multilayer actuator, once he got to 12 layers, he had to wait two days for it to cure. That is totally not sustainable, especially if you want to scale up to more layers.”
The researcher’s finding suggests the process significantly reduces the curing time once the carbon nanotubes are transferred to the elastomer and baked each later for a few minutes. As the microbots operation continued to refine, the researchers are positive about reducing the thickness to one micrometer. This will lead to using the microbots in more possible applications.