DATE:
INSTITUTE:
COURSE:
SKILLS:
Fall 2025
Duke University Pratt School of Engineering
Advanced Design & Manufacturing
• Design for Manufacturing
• 3D CAD Modeling (Autodesk Fusion)
• 3D Animation (Autodesk Fusion)
• Finite Element Analysis
• Draft Analysis
Background
Meter-dosed inhalers rely on precise timing between actuation and inhalation. For many users, this coordination can be difficult, leading to reduced medication efficiency. Spacer devices help address this challenge by holding the medication plume and allowing more controlled inhalation, delivering a higher proportion of medication to the lungs as compared to a standard inhaler. Although effective, many existing spacers are bulky, inconvenient to carry, and highly clinical in appearance. For children with severe asthma and other respiratory conditions, bringing a spacer to school can be a stigmatizing experience. To address this issue, I focused on designing a compact, manufacturable spacer that is travel-friendly, kid-friendly, and visually approachable while maintaining effective performance.
With spacer
Without spacer
Inhaler spacer with face mask
Design Process
I began my design exploration by creating a mood board to define the overall tone of the product. I then explored a range of design concepts, which eventually led to the final sketch, balancing functionality, aesthetics, and manufacturability.
Mood Board
Design Exploration Sketches
Final Sketch
3D CAD Model
Introducing Flower Chamber: a stylish, manufacturable inhaler spacer designed for everyday use and effortless on-the-go convenience. The spacer combines medical effectiveness with a stylized, water bottle inspired design. It maintains full clinical functionality while remaining visually appealing. This discrete form allows children with respiratory conditions to carry and use the device confidently at school or while traveling.
All spacer components were modeled from scratch; the inhaler used for demonstration is the only external CAD file.
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Spacer Body Overview and Assembly
The spacer consists of three primary components designed for easy cleaning: the mouthpiece, the spacer chamber, and the inhaler adapter. To assemble, the user aligns the indicators on the mouthpiece and chamber, then twists the mouthpiece clockwise to engage the locking thread. The inhaler adapter attaches with a simple snap-fit by aligning the indicators and pressing the components together.
Orientation and Inhaler Insertion
When fully assembled, the spacer is held horizontally with the vented grill on the bottom. The inhaler is inserted into the adapter, and reinforced supports around the opening ensure the inhaler remains upright during use.
Medication Flow and One-Way Valve System
After actuation, the medication plume is captured within the chamber before passing through a one-way valve assembly consisting of the retainer grid, silicone diaphragm, and valve housing. These components are installed from either end of the chamber and rest on an internal ledge, preventing backflow of the medication.
Optional TPE Accessories
The design includes removable soft TPE components for cleanliness and user comfort, including protective lids and a decorative sleeve.
Animation in Autodesk Fusion
Cross-Sectional View
A cross-sectional view reveals more detail into the internal snap-fit geometry.
One-way valve assembly
Main body and bottom
Draft Analysis
A minimum 2-degree draft was incorporated throughout the model to ensure injection moldability.
Finite Element Analysis
FEA shows that the tip of the mouthpiece (PP) can withstand a load of 400 Newtons.
Cost of Labor, Burden, & Materials
A cost analysis of Labor, Burden, & Materials estimates a manufacturing cost of ~$4 per unit.
PROJECT VIDEO
