The science of 3-D printing frees a young girl’s arms to embrace the world

In the last 25 years, three-dimensional printing has vaulted from a science-fiction fantasy to a plethora of practical, real-world applications. And one of those has opened a new lease on life for a special little girl.

Construction of 3-D objects by printing layer upon layer of super-thin plastic or metal materials has become an important technique for designing and building all sorts of products, from medical implants to airplane wings.

How 3-D printing works

Just like a laser jet printer prints inks on paper in a pattern specified by a computer program, 3-D printers deposit microscopic layers of semi-liquid plastic using a print head or nozzle that moves back and forth across a flat bed.

The software creates designs for any supports necessary to hold up the object. The supports are printed along with the object itself, and can be broken off or soaked away once the design is complete.

Another type of 3-D printer builds up microscopic layers of fine metal powder, which are then fused together one at a time by laser beams moving across the bed, much like a laser printer head.

A 3-D printer creates tiny, detailed parts for an assistive device to help a young girl move her arms.

Video: The science of 3-D printing frees a young girl’s arms to embrace the world

A third type “prints” the design with a binding glue over succeeding layers of powder to build up a mold that can later be infused with liquid bronze to form a solid metal object.

3-D sustainability

The market for 3-D printers, and the materials used for printing, is expected to reach $3 billion worldwide by 2016, according to Forbes Magazine. Businesses are investing in 3-D printing technology for building machine parts, propellers, dental implants, and even a light-weight, sustainable car body.

According to Industry guru Terry Wohlers, 3-D printing is more environmentally friendly than traditional manufacturing because it is “additive,” that is, items are built up in layers, rather than sculpted or cut from large blocks of material. Parts can be made on-site, which reduces shipping costs and associated pollution.

3-D printing also benefits businesses by cutting down on the time needed to create a workable prototype and make adjustments to the design. It also makes it possible to create much more intricate and aerodynamic objects, and helps avoid expensive errors.

Biomedical miracles in 3-D

In the biomedical engineering field, 3-D printers have been used to make individually fitted dental crowns, bridges and caps, as well as hearing aids and orthopedic implants.

For 2-year old Emma Lavelle, born without the ability to use her arms, a 3-D printer sitting in a Wilmington, Delaware, hospital became the source of tiny robotic arms that freed her from this devastating limitation.

Tariq Rahman, head of pediatric engineering and research, and Whitney Sample, research designer, both of the Nemours/Alfred I. duPont Hospital for Children, had already succeeded in helping older children with the same diagnosis as Emma.

Together they had created an assistive device made of hinged metal bars and resistance bands, all supported by a wheel chair. The device, named the Wilmington Robotic Exoskeleton (WREX), provided support and flexibility for stiff, weak muscles.

Emma’s “magic arms”

But Emma, who only weighed 25 pounds at the time and did not use a wheel chair, needed something smaller, lighter and more delicate.

Using a Stratasys 3-D printer, Sample designed similar, but tinier parts and printed them with ABS plastic, which is tough, human-friendly and similar to the material used for Legos.

The new, lighter weight WREX, attached to a small plastic vest, allows Emma to play with toys, wave her arms and feed herself. The WREX is so durable, she wears it at home, at preschool and for therapy visits.

Now six years old, Emma has been fitted into a second, larger vest. When something breaks, her mother can email a photo of the piece to the research lab. There, Sample can change the design if needed and promptly print another one, which can even be mailed to Emma’s home! The pieces are easy to attach, so that Emma’s mother can replace them herself.

Emma’s “magic arms” proved to be such a wonderful invention that now fifteen more children have been fitted with a WREX, as the blessings and benefits of 3-D printing technology spread.

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