Although robotics has developed greatly in recent years, creating microrobots (e.g., robots that are less than 1 gram) that are able to perform complex behavioral patterns still poses a significant challenge. It is mostly because of the lack of microactuators that have high work densities and can use power sources with specific energies that can be compared to these of animal fat. Find out how the RoBeetle can change that.
Right now, most of the microrobots are powered by actuators that are electrically driven. Thus, they are dependant on external power sources through cables of electromagnetic fields. That is why RoBeetle, an 88-milligram crawling robot that is barely the size of a beetle, autonomous, and fueled by methanol presents huge opportunities.
The microrobot’s body itself is a fuel tank. The operator can place a syringe in a fuel hole and fill the tiny box with methanol. The robot does resemble an insect, it is “ quadruped, more or less, with fixed hind legs and two front legs attached to a single transmission that moves them both at once in a sort of rocking forward and up followed by a backward and down motion.
The transmission is hooked up to a leaf spring that’s tensioned to always pull the legs backward, such that when the robot isn’t being actuated, the spring and transmission keep its front legs more or less vertical and allow the robot to stand. Those horns are primarily there to hold the leaf spring in place, but they’ve got little hooks that can carry stuff, too”, as reported by IEEE Spectrum
Methanol is a liquid fuel and it can hold more energy per unit volume than batteries do. This is exactly why the microrobot RoBeetle does not need any power socket or electromagnetic fields. It has enough space to be fueled for approximately 2 hours. The next challenge for the researchers will, thus, be finding solutions for efficiently refueling the RoBeetle so it can be continuously running.
While RoBeetle is small in size, it can haul objects that are almost 3 times of its own weights and can navigate different types of surfaces, everything from foam sleeping pad to sidewalk.
Source: IEE Spectrum, video courtesy of Science Robotics/University of Southern California
What opportunities can the microrobot RoBeetle present?
One it is developed enough to be able to communicate with the operator, it can for example be used to assist in complex surgeries.
What limitations does the RoBeetle have?
The microrobot can only move forward and it is not able to steer. Its speed can not be adjusted and controlling it is challenging. Once RoBeetle is in motion, it will keep moving until it runs out of fuel. So there are all elements that need to be worked on.
How will the RoBeetle be improved?
The scientists are planning to arrange the “multiple fiber-like thin artificial muscles in hierarchical configurations similar to those observed in sarcomere-based animal muscle,” which will allow the microrobt RoBeetle to become even more similar to an actual beetle and will assist in improving its pace, and efficiency.