Realization of origami-inspired smart structures using electroactive polymer (EAP)

Robert Lang has brought functionality to origami, the art of paper folding, by developing an extensive series of "action origami" figures. As the name suggests, these figures can perform actions and produce an output motion with the help of manual actuation, unlike traditional origami. For instance, different figures can bite, row, and fly. The goal of this research study is to adapt a few of these action origami figures put forth by Robert Lang to create 'active' action origami; these systems, instead of relying on manual actuation for motion, will rely on electro-mechanical actuation. This electro-mechanical actuation will be achieved through the judicious use of an electroactive polymer known as P (VDF-TrFE-CTFE) terpolymer. The terpolymer's in-plane motion in response to an electric field is converted into bending using a unimorph configuration. This bending motion is exploited to actuate three so-called "action origami" structures: the flapping butterfly, the catapult, and the barking dog. Based on knowledge of the kinematics of the origami structures, multilayered terpolymer actuator is placed strategically on the origami figures with an aim to maximize the resulting actuation motion. In order to understand the behavior, capabilities, and limitations of the terpolymer as an active material, both qualitative and quantitative data are collected from the actuation of these three different action origami structures as a function of number of terpolymer layers, applied electric field and frequency of the applied field. The goal is to find the suitable shapes and crease patterns of the structures as well as the configurations with the terpolymer film to maximize the actuation. These three structures are tested and results show that PVDF-terpolymer is an effective actuator with ability to deform a substrate to a desired shape in the presence of an electric field: the butterfly was able to flap, the mouth of the dog was able to "bark," and the catapult was able to launch a small ball of paper. Through experimentation, it was determined what parameters affect actuation and furthermore what values of those parameters will maximize the actuation.