Of special interest in the growing field of origami engineering is self-folding, wherein a material is able to fold itself in response to an applied field. In order to simulate the effect of active materials on an origami-inspired design, a dynamic model is needed. Ideally, the model would be an aid in determining how much active material is needed and where it should be placed to actuate the model to the desired position(s). A dynamic model of the origami waterbomb base, a well-known and foundational origami mechanism, is developed using adams 2014, a commercial multibody dynamics software package. Creases are approximated as torsion springs with both stiffness and damping. The stiffness of an origami crease is calculated, and the dynamic model is verified using the waterbomb. An approximation of the torque produced by magneto-active elastomers (MAEs) is calculated and is used to simulate MAE-actuated self-folding of the waterbomb. Experimental validation of the self-folding waterbomb model is performed, verifying that the dynamic model is capable of accurate simulation of the fold angles.

Action origami is a field of origami dealing with models that are folded so that in their final, deployed state they exhibit motion. Hundreds of action origami models exist, many of which use complicated kinematics to achieve motion in their deployed state. A better understanding of the mechanisms used to create motion in action origami could be a foundation for developing a new source of concepts for deployable, movable engineering solutions. This brief presents an approach for evaluating and classifying the mechanisms that enable action origami motion. Approximately 130 action origami models are investigated. Although disguised with artistic elements, it is found that most action origami models are based on a few fundamental mechanisms. A classification scheme is proposed, and an unexplored class of action origami is identified as an area for future origami art.

This paper presents the conceptualization and modeling of a compliant forceps design, which we have called Oriceps, as an example of origami-inspired design that has application in a variety of settings including robotic surgeries. Current robotic forceps often use traditional mechanisms with parts that are difficult to clean, wear quickly, and are challenging to fabricate due to their complexity and small size. The Oriceps design is based on the spherical kinematic configurations of several action origami models, and can be fabricated by cutting and folding flat material. This design concept has potential implementation as surgical forceps because it would require fewer parts, be easier to sterilize, and be potentially suitable for both macro and micro scales. The folded and planar characteristics of this design could be amenable to application of smart materials resulting in smaller scale, greater tool flexibility, integrated actuation, and an adaptability to a variety of tool functions. The suitability of shape-memory materials for use in Oriceps is discussed.

Self-folding origami has the potential to be utilized in novel areas such as self-assembling robots and shape-morphing structures. Important decisions in the development of such applications include the choice of active material and its placement on the origami model. With proper active material placement, the error between the actual and target shapes can be minimized along with cost, weight, and input energy requirements. A method for creating magnetically actuated dynamic models and experimentally verifying their results is briefly reviewed, after which the joint stiffness and magnetic material approximations used in the dynamic model are discussed in more detail. Through the incorporation of dynamic models of magnetically actuated origami mechanisms into the Applied Research Laboratory's trade space visualizer (atsv), the trade spaces of self-folding dynamic models of the waterbomb base and Shafer's frog tongue are explored. Finally, a design tradeoff is investigated between target shape approximation error and the placement of magnetic material needed to reach a target shape. These two examples demonstrate the potential use of this process as a design tool for other self-folding origami mechanisms.

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