Can a Fish Spot 3D Printed Coral?
Have you wondered what it takes to use a 3D printer, or to make a dress that can move on its own and light up? What about being able to make just about any model for a class, or being able to put a temperature, humidity, or methane sensor out in your yard to understand your local ecosystem? We have been at Windward for a little while helping people think about how to use these new “maker” technologies, and we will be writing this blog periodically to tell you about cool things Windward faculty and students are doing.
One of the first projects we have been working on is with science teacher Tom Haglund. Tom and his students wanted to know whether fish would be able to tell the difference between real coral and coral that was the same shape, but 3D printed.
Making a 3D print requires three steps: coming up with a 3D model of what you want to create, then “slicing” the model into layers a printer can build up step-by-step, and then finally loading it onto the printer.
One way to do the first step is by using a 3D scanner to “copy” an existing object, like a piece of coral. Scanners need to illuminate the interior of the structure, so scanning something like a piece of coral can be tricky. If the structure creates shadows on some parts of itself (like a partially-closed hand) the light beam(s) that the scanner uses to capture an image of the surface can’t get to the partially-shadowed structures. Right now, that requires some patience and manual fiddling to overcome. We helped the Science Department’s lab techs Regina and Glen overcome these obstacles to get some great scans.
Here's a picture of Regina comparing the original piece with the computer model that is ready to print.
Since the 3D printer starts printing from the bottom and lays up a layer at a time, if part of the coral sticks way out the programs used in the middle step of preparing a 3D print create “support.” In the picture below you can see some of the full-sized pieces of coral (and their support structure) being built up. 3D prints can take a while (some of these prints took just about a day to print) but fortunately Windward has a lot of capacity and could print three pieces at once.
In the final picture here you can see a mix of printed pieces and original real coral. Can you tell the difference? Will the fish be able to? Stay tuned for our next installment when Tom puts them in his fish tank.
Got a project you would like to try out with 3D printing, robots, sensors or other technology? Joan and Rich are both at Windward on Wednesdays and Joan is here one other day a week. Drop by room 425 to see what’s possible.