5. Expected twists and turns

If a certain usability of 4D objects can be developed, at least in specific application niches, the scientific approach must lead to results that go beyond approximate proofs of concept. To achieve consistent performance, it's essential to understand what happens during printing and stimuli, and how this affects the 4D effect. Reductive optimization for the application, which achieves consistent performance, requires accurate predictions of performance from a candidate model based on many of the properties presented in this article. But, to go further, we need to find paths that lead to robust manufacturing procedures that alone can technically satisfy industrial operation (with ISO 9000-type quality standards consistent with other devices in use).