Clayton Grames

A Classification of Action Origami as Systems of Spherical Mechanisms

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.

Oriceps: Origami-Inspired Forceps

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.Copyright

An Approach for Understanding Action Origami as Kinematic Mechanisms

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. Understanding the kinematics of action origami could result in a new source of concepts for deployable, movable engineering solutions. This paper presents an approach for evaluating and classifying the mechanisms that enable action origami motion. Approximately 300 action origami models are studied. 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 a previously unused class of action origami is identified as an area for future origami art.Copyright

Design and Fabrication of Millimeter-Scale Crossed-Cylinder Wrist Mechanism with Two Degrees of Freedom

This paper describes the design and fabrication of a 2-DOF wrist mechanism suitable for fabrication with maximum dimension on the order of 2–4 mm. The design is based on the idea of 2 half-cylinders in contact such that their axes lie orthogonal to each other. In that way, each cylinder can roll parallel to the other cylinder’s axis, giving 2 rotational degrees of freedom. To constrain the cylinders’ motion, unique gear teeth are designed that allow rolling motion in either orthogonal direction, but constrain all other motions. Contact can be guaranteed using a compressive force acting to push the cylinders together. We first demonstrate the design at centimeter scale using FDM 3D printing. Based on the smooth motion achieved, we fabricate a wrist with maximum dimension of 3 mm using layered sheets of carbon nanotube composite material. Each sheet is individually patterned using photolithography.

A Meso-Scale Rolling-Contact Gripping Mechanism for Robotic Surgery

A new, compact 2 degree-of-freedom mechanism 4.1 mm in diameter suitable for robotically controlled surgical operations is presented. Current commercially available robotically controlled instruments achieve high dexterity defined by three degrees of freedom and relatively confined swept volume at just under 1 cm in diameter. Current smaller diameter instruments result in high part count and large swept volumes (less dexterity). A meso-scale rolling contact gripping mechanism is proposed as an alternative. The manufacturing of the parts is made feasible by Metal Laser Sintering, which can produce parts that are difficult to replicate with traditional manufacturing methods. The resulting instrument has only 6 parts and a small swept volume. Instrument actuation and control by a surgical robotic system is demonstrated.Copyright