Boston, MA. BIOMEDevice presenter Gil Robinson treated attendees to a summary of the history of 3-D printing—from the time that Scott Crump pioneered fused deposition modeling (FDM) by mixing wax and plastic formulae in his family kitchen. In his presentation titled “3D printing revolution,” Robinson explained that Crump went on to cofound Stratasys, where Robinson works as an applications and pre-sales engineer. Meanwhile, Objet was pursuing PolyJet technology, Robinson said, adding that the two companies merged a year and a half ago.
The combined company serves a variety of application spaces: automotive, medical, dental, aerospace and defense, and education—everything from toys to architecture. The thermoplastics used in FDM, he said, are durable and suitable for industrial and food-and-drug applications. The PhotoJet approach employs photopolymer liquid resins cured using UV light and can yield flexible or rigid structures that are biomedical-compatible—able to be in long-term contact with the body or even implanted into the body. “The two technologies complement each other extremely well,” he said.
Robinson noted that traditional manufacturing techniques are subtractive—you start with a block of metal, for example, and use machine tools to machine away unwanted material. In contrast, 3-D printing is additive, in which the desired object is built up layer by layer. He described a typical product lifecycle, extending from concept through detailed design, tooling, and production. Changes at the tooling stages and later, he pointed out, can cost thousands of dollars and much wasted time.
And changes will be inevitable. No CAD diagram, Robinson said, can be a substitute for holding a prototype in your hands.
He ended his presentation by describing the case history of Emma, born with arthrogryposis multiplex congenita (AMC), a non-progressive condition that causes stiff joints and very underdeveloped muscles. At a conference for parents of AMC patients, Emma's mother discovered the Wilmington Robotic Exoskeleton (WREX), an assistive device made of hinged metal bars and resistance bands that enables kids with underdeveloped arms to function. Robinson said a 3-D printed version has proven to be sufficiently light weight and durable for everyday use, and what's more, new, larger versions can be printed as Emma grows. Read more on Emma and WREX here.