Paige, a student in Perkins School for the Blind’s Secondary Program, holds a white bumpy sphere the size of a plum in the palm of her hand. She wraps her fingers around it to feel the bumps and crevices, then exclaims, “So this is what one kind of virus looks like? It feels prickly!”
Paige is holding a 3-D printed model of a rhinovirus, which causes the common cold. Kate Fraser, a Secondary Program teacher, uses it to teach her science class about germs and viruses, a topic that students in nearby public schools are also studying.
“A person with full vision might get information from looking at a picture, but a person with a substantial visual impairment cannot,” Fraser noted. “3-D hands-on models are useful and interesting for everyone. But for someone with a visual impairment, they provide much-needed information about the shape and texture of an object.”
The ability to create models of almost anything has made 3-D printed items increasingly popular at Perkins. Look inside any classroom and you’ll see students using their sense of touch to study models of everything from microscopic viruses to huge marble columns.
Those items, including the prickly rhinovirus used in Fraser’s science class, are printed by Betsey Sennott, Perkins’ adaptive instructor, using a 3-D printer called the MakerBot Replicator 2X.
The printer, about the size of a microwave, sits on a desk in Sennott’s office, making a whirring and humming noise when it prints.
“The process from start to finish can be quite simple or really complex, depending on what you want to print,” Sennott said. “If you want to create your own designs from scratch using CAD (computer-aided design) software, it will take a lot longer than if you can find a design model to download online.”
The 3-D printer works by dispensing a plastic called PLA filament through an extruder that moves inside the machine, based on coordinates in the design file. It builds upward, layer upon layer, from the bottom on a glass platform until the item is completed. PLA filament is sold in 12 different colors, allowing items to be printed in multiple colors and color combinations.
Printing in 3-D takes patience. “Depending on how big the final model will be, the printing time can take anywhere from 40 minutes to several hours to complete,” Sennott said.
Design models, the template a 3-D printer follows to create an object, can be downloaded from websites like Thingiverse.com. It’s an online community where teachers, designers, engineers and 3-D enthusiasts have posted close to 500,000 designs for others to download at no cost.
Teachers at Perkins – where almost every lesson has a tactile component – are discovering new ways to use 3-D printed objects every day.
Wendy Buckley of the Deafblind Program, uses 3-D printed puzzles called Fittle to teach students how to read braille.
Each Fittle has embossed braille letters that spell out the name of the object across different pieces. For instance, “F-I-S-H” is printed letter by letter in braille on four puzzle pieces, which, when assembled, form the shape of a fish.
Building the puzzles not only gets her students exciting about learning braille, it also improves their fine motor skills and problem-solving abilities, said Buckley.
“Adding braille letters to a concrete object that the child can manipulate and explore helps to support their concept development,” she said. “It also helps make the connection between the word and its meaning for a blind child.”
It doesn’t stop there. An art teacher can use 3-D printed models of architecture elements so students can, for example, feel the entire 360 degrees around a cathedral column and the elegance of the curving design elements at the top.
Speech-language pathologists can use the 3-D printer to create tangible communication symbols for their students.
The symbols allow nonverbal students to communicate by using objects, which they identify by touch, to represent an object or phrase. For example, students can use a red, three-dimensional “X” to say “No, thanks,” or a green “O” to say, “Yes, please.”
Back in her science class, Fraser is already thinking about future 3-D tactile items she wants to give to students to explain natural objects or scientific concepts.
“Having these models readily available opens up a whole new world to our students,” she said.