Preston Innovation Laboratory, Rice University · Undergraduate UAV Researcher · May 2025 to present
A small delivery UAV for humanitarian use, built around a composite I formulated myself. The airframe material is edible and biodegradable, so a drone that goes down in the field leaves nothing harmful behind. My job was to make that material strong enough to fly and then design the airframe around it.
[placeholder: video] file: assets/drone/flight-test.mp4 What to capture: takeoff, a stable hover, and a payload carry. 30 to 60 seconds. Phone video is fine, landscape, keep the drone large in frame.
Flight test of the Gen-1 prototype.
[placeholder: turnable 3D CAD] file: assets/drone/airframe.glb Export the airframe assembly as GLB. From SolidWorks: save as STEP, import into Onshape, then Export as glTF binary. Under 20 MB keeps it fast on phones.
Airframe CAD. Drag to rotate, scroll to zoom.
The problem
Strength, weight, and manufacturability pull against each other. Every material and structural decision was a trade between the three.
No off-the-shelf material met the biodegradable requirement, so the material had to be developed before the airframe could be designed.
The composite had to survive flight loads and still be printable. [add: the load case or failure that drove the design most]
What I did
Requirements and roadmap. Owned the system requirements, the technical roadmap, and the design decisions from concept to a flight-ready vehicle.
Material formulation. Formulated a custom edible, biodegradable composite and iterated the composition against strength, weight, and printability. [add: how many formulations you went through and what changed between them]
Characterization. Derived the composite's mechanical and rheological properties from test data compiled in Python. Those numbers fed directly into the structural sizing. [add: which tests, e.g. tensile coupons, and the property values you are allowed to share]
Airframe design. Modeled the airframe in SolidWorks around the composite's properties and the additive manufacturing constraints.
FEA. Validated stiffness-to-weight and vibration suppression before committing to hardware. [add: the mode or stress case that mattered most, and the margin]
Build and integration. Printed the structure and integrated the mechanical and electronic assembly into a flying demonstrator.
Results
41% more payload capacity than an off-the-shelf equivalent.
[add: all-up weight, payload mass, flight time, number of flights]
[placeholder: simulation / test data] file: assets/drone/property-plot.png One characterization curve (stress-strain or a rheology sweep) with labeled axes and units. Export from Python at 2x resolution.
Composite characterization data.
[placeholder: FEA result] file: assets/drone/fea-result.png Stress contour or mode shape on the airframe with the legend visible.
The first material numbers were not the real numbers. Early tensile data looked strong enough to start the build, but it did not account for deposition reliability in the printing process. The strength we were quoting was not the strength a printed part would actually have. I argued for halting the build and recharacterizing. That cost weeks and it is the reason the airframe worked. [confirm this is how you want to tell it]
Designing the structure before the material was settled. The airframe and the composite had to be solved together. Every time the formulation moved, the sizing moved with it. [add: one concrete example of a redesign the material forced]
[add: the biggest thing that broke, failed, or surprised you on the Gen-1 build or flight]
How I would improve it
Characterize printed coupons, not cast ones. The property set has to come from parts made the way the airframe is made.
Lock the material before sizing the structure, and write down the property values the design is allowed to assume.
[add: one process change you would make on the next build]
Next steps
Environmental testing. A biodegradable composite has to hold its properties through humidity, heat, and time in the field. Nobody has measured how fast it loses strength. [confirm this is an open question]
Flight testing with real payload masses to turn the 41% number into flight time and range figures.
Gen-2 airframe: [add: the target, e.g. weight reduction, larger payload bay, fewer printed parts].