An improved flutter drive was developed –

The electromechanical effects provide wing flutter: Scientists have developed a clever propulsion system for flapping flying robots that does not require conventional motor and gear technology. Tests show that lightness does not come at the expense of efficiency: the system can carry insect-like flying robots through the air with great power and energy efficiency. Developers say the uncomplicated propulsion concept could pave the way for smaller, lighter, and more effective microwattling robots for environmental monitoring or rescue operations.

Propeller-driven drones are now dominant in small aircraft. In addition, however, there are already approaches that in nature are more model-based on flight technology. Flying wing flap robots can also offer some benefits in some application areas. The system can be used mainly by very small devices, which are cheap for some purposes: thanks to flapping wings they achieve better maneuverability and flight stability, and moreover, they work very quietly compared to propellers.

So far, however, a technical catch has emerged: the wings of micro flying robots are usually propelled up and down by motors, gears, and other complex drivelines. These concepts involve technical complexity, energy waste, weight and undesirable dynamic effects. In this way, the drive system loads the existing constructions, and above all significantly limits their ranges.

Direct instead of indirect power transmission

To develop better solutions, scientists working with Tim Helps at the University of Bristol once again looked at nature as a model. In biology, as is known, there are no cogs or rotating gear parts – instead, the muscles provide the wing movements. Based on bees and collaborators, scientists have developed a type of artificial muscular system that can provide beating movements in innovative ways. Instead of rotating gear parts and components, a so-called liquid-enhanced slide actuator (LAZA) uses electrostatic forces to trigger up and down movements. “The forces are converted directly into the movement of the wings, not via a complex, inefficient transmission system,” says Helps.

The base of the LAZA wing forms a negatively charged electrode rod. It lies between two outwardly curved electrodes. If they now alternately receive a negative or a positive charge, the wing rod in the center is deflected up or down by the respective attraction forces. The effect is enhanced by a drop of liquid dielectric in the base of the wing. By adjusting the gas exchange frequency, the impact effect can be set at different speeds.

Light, uncomplicated, yet powerful

To show that this system can successfully propel the wing, scientists built a prototype of a micro-flying robot the size of a dragonfly: they attached transparent plastic wings to the LAZA beating elements. Flight test evaluations with this micro flying robot have shown that: the LAZA concept can even give a flapping wing more power than the muscles of insects of the same weight. Scientists reported that the energy-saving drive was able to propel the micro-flying robot through the air at a speed of 18 body lengths per second. The system is apparently also robust: it beats evenly and reliably even in continuous operation.

Scientists say the LAZA system could now become a fundamental building block in the development of autonomous, insect-like flying robots. “It enables performance in a simpler design. This could create a new class of low-cost and lightweight microfinance robots for future applications, ”says Helps. Senior author Jonathan Rossiter of the University of Bristol continues: “LAZA is an important step towards autonomous flying robots that can be as small as insects. For example, they can pollinate plants at some point or perform tasks such as finding people in collapsed buildings. “

Source: University of Bristol, article: Science Robotics, doi: 10.1126 / scirobotics.abi8189

Video © Dr Tim Helps / University of Bristol

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