4D Printing, Volume 2

2Energy Stimulation: The Abandoned Child?

The Scientific Revolution was not a revolution of knowledge but primarily a revolution of ignorance. (Harari 2015)

We can be ignorant of a great many things without it affecting our daily lives. Still, it is undeniable that low literacy decreases our understanding of our environment especially when coupled with meta-ignorance (ignorance of one’s ignorance). (Larivée and Sénéchal 2019)

2.1. Introduction

The introduction of additive manufacturing from a privileged relationship between digital and physical realization is starting to transform the manufacturing industry. This attractive technology still has some drawbacks such as printing speed, surface finish of the final product and lack of fully functional materials. 4D printing is the additive manufacturing of active or smart materials with sensitivity to energy stimuli (e.g. moisture, pH, heat, light, solvent, electric or magnetic field). The previous chapters have focused on material–stimulus relationships, additive manufacturing strategies and the time required for shape- and/or property change to occur.

Thus, from a perceptive system to a stimulation associated with a more or less complex structure, a 4D object is able to make the equivalent of a decision (form and/or functionality) which may be revisited in future energetic interactions depending on the effects produced. This last learning mechanism has been considered: the contingencies at time t are then reversed at time ...