FMSG: Shape-programmable elastic-plastic tubes as building blocks for origami

The art of origami converts two-dimensional sheets such as paper into complex 3D shapes. In recent years, engineers and scientists have adopted origami for practical applications including deployable structures for the military or NASA, self-folding robots that can be microfabricated in thin sheet form, and actuators that respond to stimuli such as changes in temperature or acidity. This Future Manufacturing Seed Grant (FMSG) project will develop the new concept of tube origami in which complex 3D shapes are realized by bending tubes rather than sheets. This award supports fundamental research on the design and future manufacturing of tube origami, at a scale hitherto unexplored. Numerous potential applications for tube origami are anticipated, e.g. reducing the environmental impact of processes such as composite manufacturing or allowing eco-friendly techniques such as 3D printing of concrete to be adopted more broadly. This project will maintain US leadership in advanced manufacturing, promote scientific progress, and increase national prosperity. It will foster multi-disciplinary collaboration between investigators with diverse expertise in plastics processing, computational mechanics, and polymer science. The research will support the training of two graduate students at the University of Pittsburgh, and several undergraduate researchers at the University of Pittsburgh and the Penn State University. Both institutions are committed to recruiting underrepresented minorities into research. The investigators will conduct outreach at undergraduate and pre-college level on the translation of origami art towards origami engineering to attract diverse students towards STEM fields.The concept of elastic-plastic tube origami is based on two ideas. The first is that the difference between elastic versus inelastic deformation in a composite can be exploited to drive shape changes. The second is the concept of using bending of tubes (rather than bending of sheets) to create origami. This project will improve the scientific understanding of the bending mechanics of elastic-plastic composites and apply that knowledge to implement tube origami. The chief experimental tasks in this project are to manufacture bilayered elastic-plastic tubes by coextrusion, create surface "defects" on the tube using lasers, and quantify the bending of the tubes in response to pressure. The chief computational tasks are to develop 3D finite element simulations to create a predictive model for the deformation and use such simulations for rational design of the defect patterns needed to approximate any desired sequence of bending. This Future Manufacturing research is supported by the Divisions of Materials Research, Mathematical Sciences, and Civil, Mechanical and Manufacturing Innovation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.