ABSTRACT
Building a high-performance, lightweight, and durable balloon requires careful material selection. This page details the specifications for the envelope, frame, electronics, and helium, including cost analysis and supplier options.
1. The Envelope (Cover)
The envelope is the most critical component, requiring a balance of:
- Gas Barrier: Keeping helium inside.
- Optical Properties: Transmitting and diffusing light.
- Strength: Resisting pressure and tears.
- Weight: Maximizing lift.
Material Selection: Mylar (PET)
We use Biaxially-oriented Polyethylene Terephthalate (BoPET), commonly known as Mylar.
Configuration: Hybrid Design
- Upper Hemisphere (70%): Aluminized Mylar
- Thickness: 125
- Function: Blocks light escape (reflector), excellent gas barrier.
- Permeability: Extremely low (metal barrier).
- Lower Hemisphere (30%): Transparent High-Haze Mylar
- Thickness: 125
- Haze: 80-90% (Matte finish).
- Function: Diffuses LED light, creates “softbox” effect.
- Permeability: Higher than aluminized, but acceptable for short-term use.
Helium Permeability
Based on our Permeation Model:
- Rate: volume loss per 1000 hours.
- Impact: Negligible. The balloon is typically deflated/re-inflated for transport between events.
Construction Method
- Sealing: Heat Welding (Impulse Sealing) at ~200°C.
- Why not Glue?: Glue adds weight, can degrade, and is messy. Welding creates a fused bond as strong as the material itself.
- Gore Design: The sphere is constructed from “gores” (orange-slice shapes) calculated to form a perfect sphere when inflated.
2. The Frame
The internal skeleton holds the electronics and transfers the lift force from the envelope to the tether.
- Material: Carbon Fiber or Aluminum 6061-T6 tubing.
- Design: “Four-Pod” structure.
- Distributes weight over a circular base on the envelope (preventing point-stress).
- Transparent Sections: Where the frame crosses the light path, we use clear polycarbonate or acrylic rods to avoid shadows.
- Weight Target: < 200g.
3. Electronics & LEDs
LED Modules
- Spec: High-efficiency, aluminum-core PCBs.
- Candidate: TCI SML280 (Made in Italy).
- Power: ~150W per module (x4).
- Cooling: Exposed PCB back for helium convection.
Computation Center
- Microcontroller: Arduino (e.g., Nano 33 IoT or Portenta).
- Why: Low power, lightweight, built-in connectivity (WiFi/BLE), robust ecosystem.
- Sensors: Off-the-shelf modules (Bosch BME280 for Env, MPU6050 for IMU).
4. Helium Gas
- Grade: Balloon Gas (99% purity) is sufficient. High-purity lab helium is not required and too expensive.
- Supply: Standard industrial cylinders (e.g., T-size).
- Cost: ~€5-10 per .
- Recycling: For frequent use, a recovery system (compressor) can be developed, but initially, it is a consumable.
Cost Analysis (Bill of Materials)
| Component | Estimated Cost | Notes |
|---|---|---|
| Envelope | €50 - €100 | Mylar film + labor/sealing |
| Frame | €10 - €20 | Carbon/Alu tubing |
| LED Modules | €80 - €110 | 4x High-power boards |
| Electronics | €120 - €150 | Arduino, Sensors, Fans, Power |
| Cable | €20 | 50m Power/Data |
| Tethers | €10 | Nylon rope |
| Helium | €30 - €50 | Per fill (consumable) |
| TOTAL COGS | €320 - €490 | Excludes assembly labor |
SUCCESS
Even with a conservative estimate, the Total BOM Cost (< €500) allows for a very healthy margin at a €1,250 sales price, validating the business model.
Suppliers
- Mylar: EasyComposites (EU), Alibaba (China - bulk).
- LEDs: TCI (Italy), Lumileds.
- Electronics: Arduino, DigiKey, Mouser.
- Helium: Local industrial gas suppliers (SOL Group, Linde).
See Business Model for how these costs fit into the larger financial picture.