The magic of our interface lies within the plexiglass prism which creates the illusion of a hologram when an image from an LCD screen is reflected onto it. In order to bring our interface to life, we needed to obtain a large monitor and build a matching plexiglass prism. The process came with challenges, but in the end, reaped great rewards.
The first thing we had to do was consider our main limitations for prism and monitor size. We bought enormous sheets of plexiglass at the beginning of the quarter, and ideally wanted to maximize the height of the plexiglass for our display. A larger prism would require a larger monitor size, however, and deeper pockets than college students normally have. After some research and consideration, we decided that a 55″ television monitor would be sizable enough for our capstone display. We calculated the corresponding plexiglass piece to be 19″ in height.
While an Xacto knife worked for cutting the plexiglass for our small 5″ tall prototypes, we knew it wouldn’t be the cleanest solution for our large final display. We knew the University had to have laser cutters on campus available to students, so we reached out to the art and engineering departments, and attended their laser cutting orientation. After attending the laser cutting orientation, we unfortunately discovered that our piece of plexiglass was much larger than the laser cutting bed. After asking around for a larger laser cutter, we were put in contact with Matt Turner, a Physics grad student who runs the laser cutter at the Center for Experimental Nuclear Physics and Astrophysics. To our delight, he offered to cut our plexiglass pieces for free with his laser cutter! We were incredibly gracious for his help with the construction of our display.
With perfectly cut plexiglass trapezoids in hand, all that was left was to glue the pieces together into a prism. Using painter’s tape to hold the prism together and prevent silicone glue from getting all over the prism, we assembled the prism. Two pieces were glued together at a time, with a box corner holding the prism to a 90 degree angle during the drying process. After the two pieces dried, we pushed those pieces together and glued the two final edges together. Since the silicone glue dried like flexible rubber, several edges had to be reglued again and again. The silicone glue worked finely for our smaller plexiglass prism, but was not as successful at holding together our larger prism in a stable manner.
After several calculations and shopping trips to Lowe’s, we finally brought the Ghost Anatomy Project to life with our 19″ prism and 55″ monitor!
The images from the 1080p monitor project beautifully onto the plexiglass prism, giving the illusion of a 3-dimensional image sizable enough for anatomy students to study.
To fix our wobbly prism, we have decided to buy a large 24″ x 24″ piece of plexiglass to glue on top of our prism to act as a stabling lid. If the lid does not completely stabilize the prism, we are planning to switch to Epoxy instead of silicone glue. We also noticed that our display is most vibrant in the dark. We obtained permission from Tori to bring a tent to the capstone event next week, and are in the process of constructing the tent from pieces of PVC pipe and black fabric.
Hardware Shopping List:
1x 24″ x 24″ square piece of plexiglass for the prism top
3x 6.5′ long pipes
4x 5′ long pipes
4x 7′ long pipes
6x 3-pipe corner connectors
2x 2-pipe corner connectors