Turning Ideas Into Products: Expert Tips For Invention Prototypes Part 3: Proof-of-Concept Prototypes

In the first two installments of this prototyping series we examined the different types of prototypes and the different methods for making them. Over the next few articles we will spend some time talking about how to actually use prototypes as an inventor, both in the development and the commercialization processes.  
For starters, lets look at common proof-of-concept prototypes that are typically used during the early development process of your new product. Think of these prototypes as simple experiments for now. These proof-of-concept prototypes can be used for multiple purposes including:
·       Testing a functional concept
·       Demonstrating an idea
·       Working out manufacturing methods
·       Testing Materials
·       Testing Geometries
·       Exploring Aesthetics
·       Communicating an idea
·       Exploring variations
·       Identifying weak points in a design
Like all experiments, the goal with a proof-of-concept prototype is to either “prove” or “disprove” a hypothesis. Skipping this step is a great way to burn through funds and get discouraged. You want to discover dead-ends as quickly and cheaply as possible. I once helped develop a garlic press that was presented to us as having a mechanism that would dramatically improve leverage. We went all the way to pre-production prototypes based on the inventor’s claim (ignoring our process) and then finally tested it. It actually made it harder to crush the garlic! Needless to say… we were crushed.

At each point in the process of developing and commercializing a product, you have to ask yourself, what do I need to prove to feel comfortable moving forward? Am I banking on anything that I am assuming will work, but haven’t tested yet? Would a prototype help me push my project along? And, if so, what is the right type of prototype to get the result I want? The guiding principle should be figuring out the least expensive way to achieve your specific goal.  And as we stated earlier, the goal is always to either prove something works, or discover that it won’t.
You can’t expect every prototype to work, especially the early ones. Many prototypes fail (on purpose) and you want these iterations to be as inexpensive as possible.  I remember one inventor who made the first prototypes of his dusting machine with injection-molded parts. He blew all his capital on the first prototype, only to discover it needed substantial reworking. This inventors promising project died young.
There is usually a strong correlation between the realism (closeness to a production part) of a prototype and the cost. Sometimes this can be very significant. During the early stage of product development and prototyping, don’t worry about the appearance, just focus on the function.

Case in point: during the early days of my company, I can recall numerous times where we ordered expensive 3-D printed models, only to have them show up and realize they were completely the wrong size. On the computer screen the models looked perfect, but in real life it was suddenly obvious that we had the scale wrong. We learned very quickly to create size verification models out of cheap, quick, foam core profiles in order to get the gut check on the size of a part. A 60-second model can literally save you hundreds or thousands of dollars. This type of modeling is called sketch modeling. A savvy inventor will never skip this simple step.

This brings us to the general approach that I recommend for prototyping: always start with the most important and difficult-to-prove feature of the invention (what I like to call the “tallest pole in the tent”), and solve it/prove it in the most cost-effective method possible. Now, work your way down the list of problem-solving challenges and prove your solutions in each case with simple models.  Even simple and highly affordable, proof-of-concept models can be sufficient to generate confidence in a project in order to keep moving forward.
It may seem obvious to you that your invention will work based on drawings, but it may seem less obvious to an outsider that won’t believe it until he/she sees it (touches it) in person. Proof-of-concept models don’t necessarily have to look anything like the actual invention as long as they prove the principle. These prototypes don't even have to be to scale. Subsequent prototypes will get closer and closer to a final product, both in form and function, but now we are just proving that the concept has legs.
Sometimes, when a product has one or more very challenging problems to solve, a series of proof-of-concept prototypes will be made, refining the function through a series of relatively inexpensive prototypes. The overall performance can be refined with each iteration and fine-tuned until it achieves the targeted specification, at which point a higher quality more realistic prototype may be made. In the case of some particular problems, this can mean a lot of iterations. Think of Edison and his light bulb, or Dyson and his vacuums.
Proof-of-concept prototypes are a useful and simple tool that can save the inventor a lot of pain and money. Once you have proven that all the elements of your product are feasible, you are ready to move on. Your next step will involve devoting the necessary time and resources to develop a more realistic prototype that resembles the final product that will be ultimately be sold to the masses. In the next article, I will be discussing the use of prototypes later in the process to refine the parts assemblies and aesthetics. Stay tuned and as always, I welcome your questions and comments.


Part 1 - Expert Tips For Invention Prototypes - Part 1: Terminology
Part 2 - Expert Tips For Invention Prototypes - Part 2: Prototyping Methods
Part 3 - Expert Tips For Invention Prototypes - Part 3: Proof-of-Concept Prototypes
Part 4 - Expert Tips For Invention Prototypes - Part 4: Production Prototypes
Part 5 - Expert Tips For Invention Prototypes - Part 5: The Iterative Process
Part 6 - Expert Tips For Invention Prototypes - Part 6: Making A Million Dollar Product

Also, check our our Inventor Information Section on Prototyping Your Product or Invention

Chris Hawker
Trident Design LLC
Advice for Inventors Blog
- InventorSpot.com

Chris Hawker, Founder of Trident Design, LLC is an idea guy. Chris has spent the last 20 years inventing, developing and selling innovative consumer products in a variety of industries. Chris has brought numerous products to market through a variety of business models including licensing, private label manufacturing, marketing, distribution and more. To date, Chris is probably most well known for the PowerSquid, licensed to Philips—an innovative, award-winning, and commercially successful power strip.