Project · Biomimetics
Biomimetic of a Hummingbird
Hummingbirds are nature's most agile flyers, capable of sustained hover and rapid directional changes through their unique figure-of-eight wing stroke. This capstone project aimed to understand and replicate this remarkable flight mechanism through a biomimetic design approach.
I led the multi-domain analysis effort, starting with photogrammetry-based flight path extraction using image processing techniques on high-speed footage. This provided the kinematic targets for mechanism design. I then designed the wing geometry through iterative CAD modeling, arriving at optimized dimensions of 82.5mm length and 22mm tip chord.
The core challenge was synthesizing a mechanism that could achieve the required flapping motion. I designed a 4-bar linkage that converts 360° rotary input into ±60° flapping amplitude at 70Hz, while maintaining transmission angles within the feasible range (65°–114°). The complete testbed was weight-budgeted to 52 grams, accounting for motor, battery, microcontroller, and structural components.
This project strengthened my skills in mechanism synthesis, image-based motion analysis, and integrating constraints across multiple engineering domains—capabilities I continue to apply in my robotics and medical device work.
Problem Statement
- Application: Micro Air Vehicles (MAVs) that mimic biological flight offer unique advantages in maneuverability and efficiency over conventional rotary or fixed-wing designs
- Biological model: Hummingbirds, with their ability to hover, fly backwards, and execute rapid directional changes, represent an ideal biological model for biomimetic flight
- Challenge: Design a flapping mechanism that can replicate the hummingbird's characteristic figure-of-eight wing stroke pattern while operating at the required high frequency (~70Hz) with sufficient amplitude (±60°), all within the strict weight constraints (~52g) necessary for achieving lift
Methodology
The project followed a multi-domain approach: photogrammetry-based flight analysis, wing geometry optimization, 4-bar mechanism synthesis, and system-level weight budgeting. Click a stage to jump there.
Photogrammetry & Flight Path Analysis
High-speed footage of hummingbird flight (capable of capturing ~3000 fps) was analyzed using image processing techniques. The procedure involved DPI calibration using physical ruler measurements, followed by pixel-to-millimeter conversion for accurate dimensional extraction. Wing boundary tracking revealed the characteristic figure-of-eight stroke pattern, providing kinematic targets for the mechanism design phase.
Wing Design & CAD Modeling
The wing geometry was designed through iterative CAD modeling, referencing hummingbird morphology data from literature. Final optimized dimensions achieved were: wing length of 82.5mm and tip chord of 22mm. The wing was modeled as a flat, rigid structure for initial analysis, with the lift formula Lift = ρ CL v² A / 2 used for performance estimation.
Mechanism Synthesis & Kinematic Analysis
A 4-bar linkage mechanism was synthesized to convert continuous rotary input (360°) into oscillatory flapping motion (±60° amplitude). Transmission angle analysis confirmed feasibility with ηmax ≈ 114° and ηmin ≈ 65°, both within acceptable ranges for efficient force transmission. Complete position, velocity, and acceleration profiles were generated to validate mechanism performance at the target 70Hz flapping frequency.
Weight Approximation & System Integration
A comprehensive weight budget was developed for the testbed, accounting for motor, battery, microcontroller, and structural components. The total system weight was constrained to 52 grams to ensure sufficient lift generation. Component selection balanced weight against performance requirements for the 70Hz flapping frequency target.
Results
The designed 4-bar mechanism successfully converts 360° continuous rotary input into ±60° oscillatory flapping motion at the target frequency of 70Hz. Transmission angle analysis validated the mechanism feasibility with angles maintained within the acceptable range (65°–114°) throughout the motion cycle.
| Parameter | Value | Unit |
|---|---|---|
| Wing Length | 82.5 | mm |
| Tip Chord | 22 | mm |
| Flapping Frequency | 70 | Hz |
| Flapping Amplitude | ±60 | degrees |
| Input Rotation | 360 | degrees |
| Optimal AoA Range | 10-15 | degrees |
| Total Testbed Weight | 52 | grams |
| Max Transmission Angle (ηmax) | 114 | degrees |
| Min Transmission Angle (ηmin) | 65 | degrees |
Key Finding Key achievements
- Designed 4-bar mechanism achieving ±60° flapping amplitude from 360° rotary input
- Developed image processing pipeline for flight path extraction from high-speed footage
- Optimized testbed weight to 52 grams with 70Hz flapping frequency target
- Maintained transmission angles within feasible range (65°–114°)
- CFD simulations validated aerodynamic performance at 10-15° angle of attack range
Validation: Kinematic path analysis was validated through image processing comparison with literature data. Transmission angle analysis confirmed mechanism feasibility. CFD simulations (performed by team members) validated aerodynamic performance at the specified angle of attack range.
Skills Technical skills demonstrated
- Image Processing: Photogrammetry, DPI calibration, pixel-to-mm conversion
- Mechanism Design: 4-bar linkage synthesis, transmission angle analysis
- CAD: Wing geometry modeling, assembly design
- Kinematics: Position, velocity, acceleration analysis
- Systems Engineering: Weight budgeting, component selection
Team Contributions & credits
Acknowledgements: Guided by Mr. Sachhidananda M H. CFD simulations performed by Rohit K Narang, Sharan Manick, and Shaunak Anup Vaidya.
Additional Information
Complete capstone project report with detailed methodology, analysis, and results.
Visual summary poster with key figures and results.