By the end of this topic, you should be able to...
respond to emerging technologies and describe the advantages and disadvantages of why designers use rapid prototyping techniques, such as: stereolithography (SLA), fused deposition modelling (FDM) and selective laser sintering (SLS).
Guiding Question
How do designers understand the relationship between users, the product and the environment?
Did You Know? In 1989, creating a single prototype took weeks and cost thousands of dollars. Today, you can send a 3D file at midnight and hold a functional part by breakfast.
Why Rapid Prototyping?
Rapid prototyping technologies—stereolithography (SLA), fused deposition modeling (FDM), and selective laser sintering (SLS)—didn't just speed up manufacturing; they democratized innovation. These additive processes build objects layer-by-layer from digital files, enabling designers to test complex geometries (internal lattices, organic curves, multi-part assemblies) that traditional machining can't produce. But here's the critical design thinking: each technique brings distinct trade-offs.
SLA uses UV lasers to cure liquid resin, delivering smooth surfaces and fine detail—ideal for appearance models or dental aligners—but parts can be brittle and expensive.
FDM extrudes thermoplastic filament through a heated nozzle, offering affordable, mechanically strong prototypes—but visible layer lines and lower resolution limit precision applications.
SLS fuses powdered nylon with lasers, creating functional parts with excellent strength and no support structures—but machines cost $100,000+ and surface finish requires post-processing.
Understanding when to use each method—balancing speed, cost, accuracy, material properties, and intended use—is what separates hobbyists from professional designers.
Case in Point
Align Technology manufactures over 600,000 custom Invisalign aligners daily using SLA rapid prototyping. Each aligner is unique to an individual patient's teeth—a manufacturing impossibility before additive technology. The precision of SLA (±0.1mm tolerance) ensures medical-grade fit, while the speed enables mass customization at scale, transforming orthodontics from a one-size-fits-all industry into personalized care.
Learning Goals
In this topic, you'll explore how SLA, FDM, and SLS work at the technical level, evaluate their strengths and limitations through real-world applications, and learn to select the optimal rapid prototyping strategy for your IA project's specific requirements.
Linking Questions
What ergonomic aspects should be considered when selecting prototyping techniques? (A1.1)
How are concept models used to generate user feedback in a user-centred design (UCD) approach? (B1.1)
Why are different prototyping techniques used as part of the design process? (B2.1)
How does a good understanding of prototyping techniques help designers approach modelling and prototyping of their potential design solutions? (B2.2)
How can prototyping techniques be used to evaluate the appropriateness of material selection? (B3.1)
To what extent can virtual prototypes and simulations model real-world situations involving structural, mechanical and electronic systems? (B3.2, B3.3, B3.4)