Fully-printed metamaterial-type flexible wings with controllable flight characteristics

Abstract

Insect wings are an outstanding example of how a proper interplay of rigid and flexible materials enables an intricate flapping flight accompanied by sound. The understanding of the aerodynamics and acoustics of insect wings have enabled the development of man-made flying robotic vehicles and explained basic mechanisms of sound generation by natural flyers. This work proposes the concept of artificial wings with a periodic pattern, inspired by metamaterials, and explores how the pattern geometry can be used to control the aerodynamic and acoustic characteristics of the wing. For this, we analyzed bio-inspired wings with anisotropic honeycomb patterns flapping at a low frequency and developed a multi-parameter optimization procedure to tune the pattern design in order to increase lift and, simultaneously, manipulate the produced sound. Our analysis is based on the finite-element solution to a transient three-dimensional fluid-structure interactions problem. The two-way coupling is described by incompressible Navier-Stokes equations for viscous air and structural equations of motion for a wing undergoing large deformations. We manufactured three wing samples by means of 3D printing and validated their robustness and dynamics experimentally. Importantly, we showed that the proposed wings can sustain long-term resonance excitation that opens a possibility to implement resonance-type flights inherent to certain natural flyers. Our results confirm the feasibility of the metamaterial patterns to control the flapping flight dynamics and can open new perspectives for applications of 3D-printed patterned wings, e.g., in the design of drones with the target sound.

Flight Sound of an Insect Wing: Application of Metamaterial Concepts to Bioinspired Flapping Wings

“…The shape and the structure of the wing are important as governing its structural, aerodynamic and acoustic characteristics 10,18,27 . Therefore, we accurately reproduced the in-plane configuration of veins and membranes, while the out-of-plane structure can be simplified by assuming a uniform varying thickness from 0.45 mm to 0.1 mm (Figure 1, right) 18,28 . The top of the wing is thus naturally reinforced by its three-dimensional structure.…”

Tailoring the Mechanical Properties of High‐Fidelity, Beetle‐Inspired, 3D‐Printed Wings Improves Their Aerodynamic Performance

“…[29] These include laser-cutting, [16] molding, [30] and a few examples of 3D-printing of generic wings. [31,32] Although 3D-printing provides a straightforward way to mimic wings in nature and alter the wing design, [33][34][35] capturing the dynamic mechanical properties of insect wings remains a highly intricate problem. Developing insect-inspired artificial miniature wings for flapping drones thus continues to pose a challenge.…”

Special issue: bioinspired architectural and architected materials

“…The contribution by Zhilayev et al [18] investigates how artificial wings for flying robotic devices can be designed based on periodic honeycomb patterns. The authors start from the designs observed in insect wings and then use multi-parameter optimization to improve the flapping flight dynamics and the sound of a robotic drone.…”