Proof of concept

https://en.wikipedia.org/wiki/Proof_of_concept

In engineering and technology, a rough prototype of a new idea is often constructed as a "proof of concept". For example, a working concept of an electrical device may be constructed using a breadboard. A patent application often requires a demonstration of functionality prior to being filed. Some universities have proof of concept centers to "fill the 'funding gap'" for "seed-stage investing" and "accelerate the commercialization of university innovations". Proof of concept centers provide "seed funding to novel, early stage research that most often would not be funded by any other conventional source".[5]