Chukwunonso “Chooki” Arinze’s PhD Thesis Defense

SCULPTING FOLDING PATHWAYS THROUGH PHYSICAL LEARNING IN MECHANICAL SYSTEMS 

Creased sheets can possess an exponential number of folding pathways accessible from the flat state. This property poses an engineering challenge in the design of specialized self-folding origami patterns with one or a few prescribed folding pathways. Hence, an alternative means to eliminating undesired folding pathways via physical training is sought. Creased sheets are folded along desired folding pathways and their initially equal crease stiffnesses are allowed to dynamically evolve according to a local rule dependent on folding strain. It is found that undesired folding pathways are eliminated in saddle-node bifurcations, leaving behind only the desired folded pathway. Thus, physical folding, combined with a plasticity rule for crease stiffness, can naturally arrive at design parameters needed for non-linear behaviors that are hard to predict otherwise.