Here is a video that describes how photo elasticity can be done with a camera and computer screen and a polarizing filter or polarizing sunglasses.
I am working on a project with Dr. Ergun Akleman to create 3D structures from 2D structures. I have managed to create a structure that can fold from a 2D shape to a tetrahedron. A video of the structure unfolding is given here: https://www.youtube.com/watch?v=evGOyAA_JfA&feature=youtu.be. Some pictures of the structure are given below:
The current project is looking at creating a shape memory polymer that mimic the behavior of blooming flower tea. A video that describes how blooming flower tea is made is given here: http://www.youtube.com/watch?v=TLCnHcmhezw. This is a type of tea called “art” tea and consists of tea leaves in a compact structure that folds over a flower and opens up when exposed to hot water. A picture of the blooming flower tea is given here:
Some inspiration for this project also comes from origami robots. MIT and Harvard have created an origami robot that can assemble itself and move from a 1-Dimensional structure. A video of the robot is given here: http://www.tested.com/tech/robots/463382-brief-mit-origami-robot-walks-away-laser-cutter/.
In order to work on this project, I have tried some flower baking molds at various degrees of temperatures. However, there is some difficulty in obtaining the proper folding technique for the opening of the flower. The picture below depicts a flower from the baking mold. I have made one with a glass transition at 70 C and one with a glass transition at 30 C. Since the flower from the baking mold is very flat on the back, the structure does not yield to folding in very well.
Next I tried laser-cutting a flat 2D shape of a flower and folding it in. Pictures of the flat 2D shape are given below.
I have uploaded a video of the shape memory polymer flower blooming here: https://www.youtube.com/watch?v=y7iQLhYO4_U&feature=youtu.be
There is a video of an antenna made from shape memory alloy. The video is given here: http://shelf3d.com/RGDufoVQ7hg#Chiral%20shape%20memory%20alloy%20antenna. The antenna is seen below:
This auxetic shape was achieved using shape memory polymer, as well. Jonathan Rossiter and collaborators at the University of Bristol, have created the chiral structure. An image below describes how the auxetic structure works:
The structured made from the shape memory polymer is given below:
Incorporating a structure like this one might be useful for my purposes.
1. Rossiter, J. et. al., Shape Memory Polymer Hexachiral Structures with Tunable Stiffness. Smart Materials and Structures. 23 (2014).
Xie et. al. has created a shape memory material that contains multiple “temporary shape” through creating a layered polymer material. This material was created by layering two polymers with different glass transition temperatures. The first layer was made from a mole ratio of 1.6 mole Epon 826/0.4 mole NGDE/1 mole Jeffamine. It was placed in the mold and cured at 100 deg C for 40 minutes. The second layer was made from a mole ratio of 0.8 mole Epon 826/1.2 mole NGDE/1 mole Jeffamine. This mixture was poured on top of the first layer and cured for an additional 40 minutes at 100 deg C. Then the mold was post-cured at 130 deg C for 1 hour. The first layer had a Tg of approximately 48 deg C and the second layer had a Tg of approximately 75 deg C. The figure below shows the shape setting and recovery process.
Scott Rauscher M.S. from the University of Pittsburgh is entitled Testing and Analysis of Shape-Memory Polymers for Morphing Aircraft Skin Application. His thesis focuses on the development of aircraft wings that can change geometry to create optimal behavior during all flight times. He approach is to create a structurally reinforced shape memory polymer material with the reinforcement containing an embedded heating element. For the heating element, he incorporates Nickel-chrominum wire. There are two tables from his thesis below that give the properties of Nichrome wire:
His resulting embedded Nichrome sample is given below:
This artist is using shape memory polymers with laser cut patterns. This research is called active patterns which looks into using shape memory polymers as active facade materials. The temperature at which the material moved is determined by altering the ratio of its chemical makeup. The overall “behavior” is thus programmed through the geometry of the pattern cut/scored into the polymer. These polymers are made as a part of project BlackBox Smart Geometry (1).
Surface Test 1 of Shape Memory Polymer: http://vimeo.com/27825310
Surface Test 2 of Shape Memory Polymer: http://vimeo.com/27921902