The next question is connecting the piezoelectric drives to the solar energy source. Piezoelectric actuators require high voltage (200 V) and fast switching (200 Hz oscillations). These parts were assembled by blending finished and handmade components.
The final design involves placing the solar panels on a handle, a bit like an umbrella. This is done to protect the panels from airborne disturbances driven by the wings. Electronics, on the contrary, is left hanging on the bottom of the robot, providing little balance. The whole package is only 90 milligrams and has a weight ratio of 4: 1. The authors call the little awkward RoboBee X-Wing result.
How does it work? Well, the included video shows that it flies but is extremely short; typical flights are for less than half a second and require three light sunlight. The authors call it "sustainable," which seems to be stretching the definition of the word. The robot mostly deals with control simply by not flying long enough to deal with it.
But there are some significant opportunities for improvement. While the existing robot weighs only 90 milligrams, it can produce more than 350 milligrams of lift. The authors believe that they could almost double the weight of the vessel, while retaining a sufficient lift for decent work. In itself, this can easily be used to expand solar panels, increase power, switch on board sensors, or place the vessel control system – or perhaps more than one.
The current RoboBee X-Wing design also has many overhead to improve. The authors suggest that they can redesign the drive mechanisms to reduce the required voltage by half, which will allow them to simplify the voltage transformation electronics. It is almost certain that the electronics can be miniaturized, which will further reduce the weight. Another tuning of the electronics should allow the robot to recover some of its electricity, effectively increasing the available power. Researchers also want to look at how the air interacts with the robot's four wings to optimize further.
This is a great place for improvement and there is no doubt that RoboBee Mark II will one day be closer to the flight. can legitimately be described as "sustainable". In this sense, the RoboBee X-Wing should be seen as the second prototype, following the first version designed for innovative technology. The dispute over the use of the word "lasting" is irrelevant, as the purpose of this machine is to find out if the solar powered version actually puts the hardware on the right path to get on a permanent flight, perhaps with
Nature 2019. DOI: 10.1038 / s41586-019-1322-0 (for DOIs).