
 This paper presents the development of an origami-inspired support system (the OriGuide) that enables the insertion of flexible instruments using medical robots. Varying parameters of a triangulated cylindrical origami pattern were combined to create an effective highly compressible anti-buckling system that maintains a constant inner diameter for supporting an instrument and a constant outer diameter throughout actuation. The proposed origami pattern is composed of two repeated patterns: a bistable pattern to create support points to mitigate flexible shaft buckling and a monostable pattern to enable axial extension and compression of the support system. The origami-based portion of the device is combined with two rigid mounts for interfacing with the medical robot. The origami-based portion of the device is fabricated from a single sheet of polyethylene terephthalate. The length, outer diameter, and inner diameter that emerge from the fold pattern can be customized to accommodate various robot designs and flexible instrument geometries without increasing the part count. The support system also adds protection to the instrument from external contamination.

/pdf/an-origami-based-medical-support-system-to-mitigate-flexible-1ddz10c8mn.pdf

An Origami-Based Medical Support System to Mitigate Flexible Shaft Buckling

Polyethylene terephthalate (PET) sheets show promise for application in origami-based engineering design. Origami-based engineering provides advantages that are not readily available in traditional engineering design methods. Several processing methods were examined to identify trends and determine the effect of processing of PET sheets on the crease properties of origami mechanisms in PET. Various annealing times, temperatures, and cooling rates were evaluated and data collected for over 1000 samples. It was determined that annealing temperature plays the largest role in crease response. An increase in the crystallinity of a PET sheet while in the folded state likely increases the force response of the crease in PET sheets. An annealing time of at least 60 min at 160-180 C with a quick cooling results in a high force response in the crease. The effectiveness of the processing methods was demonstrated in several origami patterns of various complexities.

/pdf/heat-set-creases-in-polyethylene-terephthalate-pet-sheets-to-5g7asujhul.pdf

Heat set creases in polyethylene terephthalate (PET) sheets to enable origami-based applications

Compliant polymer origami bellows in cryogenics

During the 1990s, the development and application of mathematical techniques to origami revolutionized this centuries-old Japanese art of paper folding. In his talk, Lang will describe how geometric concepts led to the solution of a broad class of origami-folding problems. Conversely, algorithms and theorems of origami design have shed light on long-standing mathematical questions and have solved practical engineering problems. Lang will discuss how origami has led to huge space telescopes, safer airbags, and more.

From Flapping Birds to Space Telescopes: The Modern Science of Origami (BNL Women in Science Lecture)

Compliant joints have a number of advantages that make them suitable for highly constrained design problems. While much work has been done on the design of compliant joints manufactured from planar sheet materials, this work focuses on the design of cylindrically-curved joints. A method for using lamina emergent torsional (LET) joints to increase energy storage efficiency in curved sheet materials is presented. A numerical model is provided for predicting the stiffness and maximum applied moment of a curved LET joint. Predicted curved LET joint stiffnesses and maximum moments are utilized to create shape factors that produce an effective modulus of elasticity and an effective modulus of resilience. For a given case, the effective modulus of elasticity is shown to decrease by about three orders of magnitude while the effective resilience decreases by approximately one order of magnitude. Designers can use this information to tailor materials to fit design requirements or to select alternative materials that were previously unsuited for an application.

https://par.nsf.gov/servlets/purl/10092370

Modified Material Properties in Curved Panels Through Lamina Emergent Torsional Joints

The design and testing of an origami-based bellows for microgravity drilling is described. The potential benefits of an origami-based solution created an opportunity for application on NASA’s Asteroid Redirect Mission (ARM) to protect sensitive parts from debris. Origami-based bellows were designed to fit spatial limitations and meet needed compression ratios. Designs have demonstrated high mass reductions, improved stroke length, greatly decreased stowed volume, improved flexibility, and reduced reaction forces in comparison with traditional metal bellows. A nylon-reinforced polyvinyl fluoride based bellows with an aramid fiber stitched seam is well suited for debris containment in space conditions. Various epoxies maintained an adequate bond with polyvinyl fluoride below expected environmental temperature for bellows mounting. Asymmetric compression of the bellows occurs at extreme low temperatures and is preventable by balancing stiffness within the structure.

/pdf/highly-compressible-origami-bellows-for-microgravity-2n8p7sbphh.pdf

Stefano Mancini

Papers

Highly compressible origami bellows for microgravity drilling-debris containment