Study of Mosquito Aerodynamics for Imitation as a Small Robot and Flight in a Low-Density Environment

Abstract

In terms of their flight and unusual aerodynamic characteristics, mosquitoes have become a new insect of interest. Despite transmitting the most significant infectious diseases globally, mosquitoes are still among the great flyers. Depending on their size, they typically beat at a high flapping frequency in the range of 600 to 800 Hz. Flapping also lets them conceal their presence, flirt, and help them remain aloft. Their long, slender wings navigate between the most anterior and posterior wing positions through a stroke amplitude about 40 to 45°, way different from their natural counterparts (>120°). Most insects use leading-edge vortex for lift, but mosquitoes have additional aerodynamic characteristics: rotational drag, wake capture reinforcement of the trailing-edge vortex, and added mass effect. A comprehensive look at the use of these three mechanisms needs to be undertaken-the pros and cons of high-frequency, low-stroke angles, operating far beyond the normal kinematic boundary compared to other insects, and the impact on the design improvements of miniature drones and for flight in low-density atmospheres such as Mars. This paper systematically reviews these unique unsteady aerodynamic characteristics of mosquito flight, responding to the potential questions from some of these discoveries as per the existing literature. This paper also reviews state-of-the-art insect-inspired robots that are close in design to mosquitoes. The findings suggest that mosquito-based small robots can be an excellent choice for flight in a low-density environment such as Mars.

Keywords: flapping frequency; low-density; rotational drag; stroke amplitude; wake capture; wing flexibility.

Figure 1

Spectrum-based drone size scale. Reproduced with permission from ref. [1]. Copyright 2017, Elsevier (Amsterdam, The Netherlands).

Figure 2

(a) Structure of haltere of a fly. Ref. [13]. (b) Resilin (red) localizes to distinct regions of the fly body. (A) pupa head, (B) legs, wings, and abdomen of an adult fly, (C) head, (D,E) several tiny Pro-Resilin-GFP patches legs, wings, and abdomen, (F) tracheal endings. (G) hair bases. Ref. [14], open-access article distributed under the terms of the Creative Commons CC BY license.

Figure 3

(a) Aerodynamic representation of mosquito during flight (b) Representation of mosquito-related flapping cycle phases (c) Graphical representation of formation of leading and trailing edge vortices during phases of the wingbeat cycle of mosquito flight.

Figure 4

Stroke-based $C_L$, $C_D$, and L/D ratio in relationship with AoA and stroke amplitude. (A,C) and (E) have a mechanical model contour map based on the measured value. (B,D) and (F) showed measured values from the translational quasi-steady model using empirically measured force coefficients. Reproduced with permission from Ref. [25]. Copyright 2001, Company of Biologists Ltd. (Cambridge, UK).

Figure 5

(a) How added mass inertia contributes to an estimated total aerodynamic force with a specific kinematic pattern at 45 degrees AoA. Reproduced with permission from Ref. [25]. Copyright 2001, Company of Biologists Ltd. (Cambridge, UK) (b) Coefficients of lift and drag in a single flapping cycle with a mosquito sample in flight. Reproduced with permission from Ref. [5]. Copyright 2020, Cambridge University Press (Cambridge, UK).

Figure 6

Instantaneous vorticity dissemination of the y-component at different t/T and the velocity in the symmetric XZ plane at the center point of the wingspan: (a) the numerical simulation results; (b) the PIV results from [2]. Reproduced with permission from Ref [4]. Copyright 2019, AIP Publishing (Melville, NY, USA).

Figure 7

(a) Aerodynamic force assessment of a mosquito wing with a single flapping period. (b–d) The pressure contours showing distributions on the wing surfaces at particular t/T with instants t₁, t₂, and t₃. Reproduced with permission from Ref. [4]. Copyright 2019, AIP Publishing (Melville, NY, USA).

Figure 8

Results of streamlining for symmetrical rotation by analyzing the rigid rotating wing with α. (a) Vorticity and vertical velocity for rigid and flexible wings, (b) wing-wake interaction for rigid and flexible wings. (c) Time history of normalized lift (d) C_L^∗ relation with γ (e) Time histories of TEV, LEV vorticity with downwash. [105] Reproduced with permission from Ref. [106]. Copyright 2014 Royal Society Publishing (London, UK).

Figure 9

Quasi-steady wing (or blade) element theory modeling of mosquito wings. Reproduced with permission from ref. [144]. Copyright 2016 Company of Biologists Ltd. (Cambridge, UK).

Figure 10

A quadcopter-based model system to experimentally verify the mechanosensory collision-avoidance mechanism in mosquitoes. The copter has (A) pressure probes for maximizing deltas near proximity, (B) pressure sensing components, (C) schematic diagram of the copter (D), tube network of sensors, (E) real flying prototype, (F,G) differential pressure with close proximity to the ground. Reproduced with permission from Ref. [166]. Copyright 2020, AAAS (Washington, DC, USA).

Figure 11

3D Navier-Stokes solutions asked on Q-criterion (a) $C_L$ coefficient and time histories (b) span-wise vorticity contours for LEVs, high $C_L$ (c) LEV shedding and reduction in lift (d) enhancement using the rotational lift (TEVs). Reproduced with permission from Ref. [198]. Copyright 2021, Elsevier B.V. (Amsterdam, The Netherlands).

Figure 12

Time histories of the (a) flap power and (b) pitch power required for hovering on the red planet with different wing sizes n. Reproduced with permission from Ref. [197]. Copyright 2018, IOP Publishing (Bristol, UK).