Researchers from Harvard's John A. Paulson School of Engineering and Applied Sciences have created a robotic bee inspired from nature that can fly through the air, dive into water, swim under water and propel itself back to the air from beneath the surface of water. The RoboBee is a thousand times lighter than any aerial to aquatic robot made so far. The engineers developed novel flotation devices that allows the RoboBee to stabilise itself on the surface of the water before propelling itself into the air.
The microbot is so small that the surface of the water might as well be a brick wall. The RoboBee can dive into the water by breaking through the surface tension by using its sharp wings. Once within the water, it can use the same wings it used to fly through the air to swim through the water. Because water is more than 1,000 times denser than air, the frequency of the beating wings has to be tuned to the medium through which the RoboBee is navigating. If the wings beat too slow, the microbot cannot maintain lift and stay in the air. If the wings beat too fast underwater, they can snap off.
The researchers zeroed in on the correct wing size and flapping rate in air and water by combining experimental data and theoretical models. The wings of the RoboBee flap at 220 to 300 hertz in air, and at a much slower 13 hertz in water.
There are four flotation devices in the corners of the microbot, that collects air and allows the bot to jump out of the water. The gas chamber in the middle of the bot creates its own fuel from the surface of the water, by using an electrolytic plate to convert the water into oxyhydrogen. A tiny sparker inside the robot then combusts the gas in the chamber to propel the RoboBee outside the water. Because of current limitations in the on board electronics, the RoboBee cannot start flying immediately after jumping out of the water, but the team is looking at ways in which this can be fixed.
The research has been published in Science Robotics. Yufeng Chen, the first author of the paper says, "This is the first microrobot capable of repeatedly moving in and through complex environments. This is the first microrobot capable of repeatedly moving in and through complex environments." The RoboBee can be used in search and rescue operations, as well as environmental monitoring.
Published Date: Oct 27, 2017 04:08 pm | Updated Date: Oct 27, 2017 07:56 pm