SME Speaks: Manufacturing Engineering: It Isn't Brain Surgery -- Is It?
By Gene Nelson
Society of Manufacturing Engineers
When thinking about manufacturing engineering technologies, many engineers think first of tasks related to formulas, mechanical drawings, and the production of materials on a shop floor, but there are so many other areas touched by our work. In fact, we leave virtually no area of industry and human life untouched. Manufacturing engineers are involved with everything from buildings and bridges, washing machines, space shuttles, planes, trains, and automobiles, to high-tech running shoes, Palm Pilots, cell phones, GameBoys, pharmaceuticals, and prosthetics.
One significant area of technology where SME members are making a significant contribution is in the health care and medical profession. Engineers applying manufacturing processes to health care have helped medical professionals improve the effectiveness of treatments and their patients' quality of life.
Manufacturing engineers work on advances in pharmaceuticals, medical diagnostic equipment, and surgical tools. They are also inventing, exploring and perfecting micromanufacturing products and services that are currently, or soon will be, under consideration for approval by the US Federal Drug Administration. These members are making dreams of smaller and more effective medical implants possible, creating microdevices for use in minimally invasive surgeries, and exploring nanotechnology and micro-electromechanical systems (MEMS) as technologies that can help them with complex surgeries in the not-so-far-off future.
While widespread application of nanotechnology in medicine is still a few years away, there are many manufacturing processes and procedures at work in the medical field today. It is primarily through micromanufacturing technologies and rapid prototyping that manufacturing professionals have applied their engineering knowledge and skills to provide recent and current patients with more effective treatment.
Susan Sackman, the member advisor for SME's MicroManufacturing Conferences since 2003, is the model shop group leader for Guidant Corp., helping determine the best way to manufacture new medical devices. Andy Christensen, SME member and president of Medical Modeling Corp., has developed methods and models to assist surgeons in preparing for particularly complex surgeries. For instance, he assisted the Division of Pediatric Surgery at the University of Texas Health Science Center in Houston with the development of a craniofacial model that guided surgeons in the reshaping of a child's skull. The risky procedure, called fronto-orbital advancement with cranial vault remodeling, presents many challenges to surgeons. Without careful planning, the surgery could result in a worsening of the disfiguration, but, with data collected from a 2-D CT scan of the patient, Christensen's company prepared a 3-D model in less than four hours and, ultimately, cut time in the operating room, reduced the risks of complications, and contributed to the success of the surgery. It is only one example of many impressive medical successes made possible with the company's help.
SME member Jules Poukens, from the University Hospital Maastricht in the Netherlands, uses CAD/CAM and rapid technologies for reconstructions to correct complex defects in the face. Poukens' work includes reconstruction of skull defects using CNC-milled or hydroformed titanium plates, medical models for surgical simulations, stereolithographic surgical guides for the placement of implants, 3-D printing of bioresorbable scaffolds, and the manufacturing of facial prostheses.
Steve Schmitt of TelMed Technologies, an active member of SME's Rapid Technologies and Additive Manufacturing Community, is using CAD and rapid prototyping to produce dental castings that can reduce labor for dentists while significantly improving the quality of dental castings. And there are more great examples of manufacturing engineering in the medical field. Other SME members are using emerging scanning technologies and rapid prototyping to create miniscule hearing aid cases, helping orthodontists correctly align teeth with invisible braces, and creating biomodels of congenital cardiovascular malformations that can, ultimately, save lives.
By supporting these professionals through communities with technical groups like the Medical Applications Technical Group and the MEMS/Nano Applications Technical Group and through hundreds of other resources, SME is helping them expand and share their knowledge of manufacturing processes that make a difference for human health.
It helps us--as a Society--expand the positive and profound impact engineers have on the world. And we're proud of it.
Manufacturers Reinvent the Wheel
Engineering creativity can improve upon almost everything. The new Michelin Tweel, a nonpneumatic tire/wheel combination, is a classic example. Bart Thompson, an SME member and innovation engineer for Michelin, was one of the engineers responsible for this innovation, in which tire and wheel are bonded as a single item that's both rigid and flexible.
Current radial tires consist of a body ply--usually made of polyester reinforced rubber with two steel belts laid on the crown of the tire--and a tread pattern molded on top. Their stiffness is directly affected by air pressure. The Tweel's rigidity comes from a sheer band attached to a center wheel with extremely flexible rectangular spokes. Rubber tread is molded to the band, which is made of a specially reinforced elastomeric material. The band provides contact-patch pressure, and the flexible polyurethane spokes are extremely compliant, bending easily and allowing the structure to absorb shock, carry heavy loads, and envelope road hazards similar to a pneumatic tire. The flexible elastomeric spokes transmit load to the center wheel by holding the load in tension. In the contact area the spokes flex, thereby providing a cushioned ride similar to that provided by a pneumatic tire.
The greatest value the Tweel offers over existing radial tires is its durability. The Tweel has no single point of failure; for instance, it cannot be harmed by nails in the road. In fact, in testing, it has remained serviceable after being damaged by an exploding landmine.
While the Tweel is still only a concept when it comes to use on passenger cars, it's already available for use on the iBOT-a mobility device invented by Segway inventor Dean Kaman. Manufacturing engineers are busily refining the Tweel in order to reduce excessive noise at speeds over 50 mph (31 kph), improve its overall performance, and begin addressing mass-production issues.
If the Tweel takes off, Thompson believes it will change the way tires are manufactured. Tire manufacturers could expect to eliminate most of the components needed to manufacture current tires and they--as well as distributors, dealers, and the end-customers--would no longer need the costly air-pressure monitors that will soon be required on new vehicles in the US. The Tweel could be used not only for passenger cars, but also on construction equipment, military applications, and in the distant future perhaps even on trucks and airplanes.
This new engineering innovation has received a good deal of visibility, both in industry and in the media. In January, Thompson helped unveil the Michelin Tweel at the North American Auto Show in Detroit. He also demonstrated the Tweel on a Segway Human Transporter on the CBS Evening News with Dan Rather that aired nationally.
If you want to learn more about the Tweel, register now to attend the 2005 SME Summit, "Where Manufacturers, Technologies and Innovations Connect," August 3 - 4 in Oconomowoc (Milwaukee), WI. As event keynoter, Thompson will discuss the manufacturing implications and challenges faced by this innovative new product, and set the stage for the rest of the Summit, where members and guests of SME's Technical Community Network will share knowledge on other new manufacturing innovations and emerging technologies.
For more information about the 2005 SME Summit, call (800) 733-4763 (US only) or (313) 271-1500, Ext. 4500 or visit www.sme.org/techsummit.
This article was first published in the May 2005 edition of Manufacturing Engineering magazine.