Prototypes are a necessary part of product design. Prototypes are important to communicate ideas, solicit market feedback, improve designs and help to de-risk the product development journey. In general, building prototypes are important to increase your chances of success in hardware. As everyone always says, "hardware is hard".
Here are the 6 types of prototypes:
Concept Sketch Prototype
Bench Model Prototype
Fully Functional Rapid Prototype
Visual Model Prototype
Pre-Production 'Alpha' Prototype
Manufacture Production Prototype
Number 1: Concept Sketch Prototype
This is the first step where your idea starts to gain some legs. You use pen, paper, iPad or anything else that you are comfortable with and you start sketching your idea. This could be how it looks, how it works and anything in between. The main idea at this stage is to quickly share your idea and get feedback.
Number 2: Bench Model Prototype
The next step is to build a bench model. A bench model is necessary to test assumptions and get answers quickly before larger design implementations. You can use this phase to answers questions such as technological feasibility or ergonomics.
Number 3: Fully functional rapid prototype
A final solution starts to come together. Using various technologies - 3d printing, laser cutting, CNC machining and others, you build a model to test and verify various functions of your product.
This version will be a very expensive version of your final product. But this will provide you with valuable feedback on size, function and interaction.
Number 4: Visual Model Prototype
A visual model prototype where the final form and feel, including all materials, will be built. This is important for marketing purposes such as crowdfunding, packaging and video shoots.
Number 5: Pre-production Alpha Prototype
An Alpha Prototype allows you to validate the look, function and production processes of your product. Several pieces may be made of the alpha prototype in order to commence user-testing. At this point, there is very little room to make changes to the design and engineering of your product.
Number 6: Manufacture Production Prototype
First products off the production line. Produced with final manufacturing techniques. Used to ensure everything fits well together and works perfectly. Important to also start figuring out quality control guidelines.