Thrust Regulation Through Wing Linkage Modulation on the Aerobat Platform: Piezoelectric Slip-Stick Actuated Regulator Development

Robotics researcher Luca Ciampaglia has published a thesis detailing a breakthrough in controlling the Aerobat, a lightweight, bat-inspired flapping-wing robot. The Aerobat's original design uses a single motor and a computational structure (a planar linkage) to drive both wings, which makes it efficient but prevents independent thrust control and asymmetric maneuvers like banking turns. Ciampaglia's work tackles this by developing a regulator that physically changes the effective length of a specific carbon fiber link (R1) in the wing's mechanism, directly modulating the thrust produced by each wing.

Through static testing with 3D-printed links at three lengths (28.58, 29.33, and 30.08 mm), the research quantified that a mere 1.5 mm extension could increase peak lift force by 37% and shift its timing within the wing stroke. After failed attempts with string-tension and micro-servo methods, the team successfully implemented a TULA-50 piezoelectric slip-stick actuator—a precise, sub-gram component that uses rapid stick-and-slip motions for fine control. This actuator was integrated into a direct-drive variable-length mechanism embedded within the wing linkage itself.

While the final bench-top prototype demonstrated the concept's viability, it currently lacks the force output needed for dynamic testing during actual flapping flight. Nonetheless, this research provides a crucial proof-of-concept: embedding compact, precise piezoelectric actuators into robotic morphing structures is a viable pathway to achieving sophisticated, independent control in ultra-lightweight flying machines, moving them closer to the agile flight of their biological inspirations.