Victoria Burt
Contributing Editor

Julie Kalista
Online Editor

What does it take to be a great engineer? One way to find out is by talking to engineers who’ve made significant contributions to their industries. Machine Design has done exactly that.

The engineers profiled in the next few pages share several traits. All faced challenges that forced them to think outside their comfort zone and beyond their personal technical bias. And they share an intense drive to solve problems, and create new designs that make the world a better place.

Refuel on your way to Mars
Dan Delong, of XCOR Aerospace, Mojave, Calif. (xcor.com), is the lead engineer on a rocket engine, developed for NASA that uses liquid methane as fuel. Delong and his team had to come up with a way for astronauts to get fuel at their destination, for example, Mars or the moon. As Delong puts it, “If you are traveling across country and cannot stop for fuel, the vehicle will be much bigger and heavier. However, if you can stop for gas along the way, you can use a smaller and lighter mode of travel.”

Delong says the team’s most-difficult challenge was in cooling the combustion chamber. The solution was to direct the fuel through carefully designed galleries. “The cooling properties of boiling liquid methane are relatively unknown, so this was a challenging design with lots of risks,” says Delong. “We overcame that by using the best analysis we could, with the most conservative cooling design.”

Inspired by his father, a lab technician who did house wiring on the side, Delong got his Bachelor’s degree in Materials Science and Engineering from Cornell. Interestingly, he didn’t start out in aerospace. His first job out of school was working with submarines and he says they fascinated him. However, in 1984, a friend encouraged Delong to work on the Space Shuttle. He says the technical aspects of the career change came easy, but he was challenged by the culture of working for the government.

Changing a company and family’s culture
With four brothers who are engineers, engineering might have seemed an obvious career choice for Susan Benysh. But she says her parents advised her and her sisters to enter traditionally female vocations such as medicine. Fortunately for Benysh, a high-school teacher encouraged her to consider engineering. She minored in electrical engineering and then discovered a school with a human-factors engineering program that combined her interest in engineering and psychology.

Benysh got her Ph.D. from Purdue and now works at IBM Corp., Rochester, Minn. (ibm.com). She recently moved to the Learning department where her title is Learning Partner. She is developing a program to teach other IBM software engineers how to design leaner and better products. She says the hardest part of the project is convincing her colleagues to adapt to a new process. “Some people resist change even when it will make their work easier. The culture is an obapplicastacle we are overcoming as people go through the classes and bring the techniques back to their departments,” Benysh says.

A package like a puzzle
Mauro Morandi was working on a different project when some colleagues asked him to help with a new carton package design. He agreed to help the team at Tetra Pak, Italy (tetrapak.com), and together they created the eye-catching, octagonal Tetra Prisma Aseptic package. An aseptic package gets sterilized before it is filled with food, resulting in products that can stay on the shelf for over six months without refrigeration or preservatives.

Morandi faced a major challenge in the final folding of the top and bottom parts of the package. “Because of the octagonal shape, we had to fold the edges twice, increasing complexity, manufacturing, and slowing output. My idea was simply to use the octagonal shape in the middle of the package and the traditional rectangular or square shape of Tetra Prisma’s predecessor, Tetra Brik packages, for the top and bottom,” says Morandi.

Growing up, Morandi always loved trying to understand and illustrate how things work. He received his diploma from the Istituto Tecnico Industriale Statale Remo Corni, in Modena, Italy, where he studied mechanics.

Let the robot do it
The well-known Roomba is the first home appliance to excite the imagination of nontechies. Made by iRobot, Burlington, Mass. (irobot.com), the autonomous vacuum cleaner is the brainchild of a design team headed up by Chris Casey, lead electrical engineer. According to Casey, Roomba’s magic is the combination of two tasks: navigating around an unstructured environment while cleaning a wide variety of floor surfaces. Equipped with navigation sensors, Roomba senses obstacles like furniture, steps, and walls. It uses only 30 W to clean as much as vacuums using more power.

Casey credits the development team for making the Roomba a reality. Scientists Joe Jones and Paul Sandin were the first to realize that a low-cost floor vacuum robot was possible. “Three engineers, Eliot Mack on mechanics, Phil Mass, and I, worked for Joe and Paul for over two years turning the concept into a product,” says Casey.

“Our biggest challenge was getting the robot to operate in a human world, while balancing conflicting needs like cost, size, cleaning ability, and navigation. We figured it out as we went — at one point we spent nearly a month testing the length of the rear shroud of the main brush.”

Fascinated by programming and the “magic” by which programs were executed, Casey knew from an early age he wanted to be an electrical engineer. He picked a good place to get Electrical Engineering credentials: He graduated from MIT and worked for a small company designing electronics before coming to iRobot in 1997.

How to make racing engines last longer
Jobey Marlowe loved mechanics from an early age. He started racing peddle cycles when he was eight-years old, but couldn’t afford more than one bike. So he found parts in dumpsters, put them together, and sold bikes for profit. That early experience sparked his interest in both racing and engineering.

Marlowe got a chance to make both areas his vocation with the Magnom separator. The separator protects engines in high-stress endurance races by filtering out iron and steel contaminants. The technology uses magnetic flux, magnifying it and focusing it into a complex matrix directed into the oil stream. It came out of Marlowe’s discovery that the metallic particles in engine oil were so small, they passed straight through conventional filters.

The biggest obstacle in developing the separator was optimizing the relationship between the contact zone of the plates involved and the magnets. Engineers made several prototypes and compared how they worked in live applications. The best features from the most-efficient prototypes went into the product on the market today.

Harold Hall, or “H” as Marlowe refers to him, is an ex-Royal Air Force engineer. He is also Marlowe’s role model. “H is a bit like the professor on ‘Back to the Future,’ same looks and mannerisms, a real sweet old guy, and a heck of an engineer. He got me seriously interested in racing and building engines. Today he still builds the most reliable race engines on the track,” says Marlowe.

I feel your psi arising
Pressures in aircraft hydraulic systems now reach 5,000 psi. Tung Le and his team had to create fasteners that could handle the pressure. As a project engineer for Alcoa Fastening Systems, Fullerton Aerospace Operations, Fullerton, Calif. (alcoa.com/global/en/home.asp), Le developed the firm’s Ring Locked Fluid Boss Adapters. They have captive lockrings that secure the adapters to the boss thus keeping connection tight under severe vibrations, temperature cycling, or B-nut installation and removal.

Le says the most challenging part of the design was convincing the industry to accept it. However, Alcoa got a break when, after passing extensive tests, Boeing agreed to use the fittings on its new 787 Dreamliner.

As a child growing up in war-torn Vietnam, Le memorized the look of aircraft, warships, tanks, trucks, and weapons he saw daily, and drew them when he got home. “This was the starting point for my entry into engineering,” he says.

Le has a degree in mechanical engineering from Vietnam’s Saigon Institute of Technology. When he came to the United States, he took engineering classes at various schools. Le credits a colleague, Owe Carlsson, director of engineering and quality assurance, as being his mentor.

A plastic that protects against x-rays
For Jay Amarasekera and his team at Sabic Innovative Plastics, (formerly GE Plastics), Pittsfield, Mass. (sabic-ip.com), the goal was clear: Find a replacement material for lead in X-ray shielding. Solving the problem, however, took experience and lots of testing. The result was LNP Thermocomp HSG compound. It is a compound based on tungsten — a nonhazardous high specific gravity material — in nylon.

The idea for the project came from the industry push to get away from lead. Amarasekera says, “the toxicity of lead has been heavily reported in the news including stories about lead paint on toys, and standards such as RoHS call for a reduction in lead use. But for X-ray shielding plastics, there were limited lead-free alternatives that had good manufacturing capabilities.” Amarasekera and team members Jennifer Doerfler, Julie Tinklenberg, and Dave Sweeley developed a plast ics composite with X-ray shielding properties resembling those of lead and optimized flow properties for easy injection molding. The team worked with customers to test the compound and develop easily manufactured grades for thin-wall applications and designs with complex geometries.

Amarasekera is the Technology Manager at Sabic’s LNP Business Unit. He has a PhD in inorganic chemistry from the University of Illinois at Urbana-Champaign and over 20 years experience working with materials. He says his career naturally progressed to engineering because he enjoys solving problems and creating new products.

Making tiny instruments for microscopic procedures
Adam Cohen’s background in rapid prototyping combined with his interest in MEMS led him to help develop electrochemical fabrication, or Efab for short. Cohen thought it should be possible to design a complex structure using 3D CAD and then make it, one layer at a time, from metal, on a wafer scale. The idea could potentially be used to fabricate hundreds or thousands of devices simultaneously.

Efab technology from Microfabrica, Van Nuys, Calif. (microfabrica.com), works by precisely depositing and polishing the surface of two metals. One of these is structural — forming the final structure — while the other is temporary and sacrificial, serving as a support or scaffolding during fabrication. Each layer involves three key steps: deposition of one metal in a precise pattern that defines a cross section of the desired structure, blanket deposition of a second material, and planarization (polishing the surface), which yields a two-material layer of well-controlled thickness, flatness, parallelism, and surface finish. After all layers are formed, the sacrificial metal is dissolved away, leaving behind the desired structure with all individual components now free to move with respect to one another.

Cohen holds 34 patents and is Microfabrica’s chief technology officer. He has a BS in physics from MIT and studied theoretical physics. But 22 years ago he made a critical decision to move out of pure science into technology. He works in engineering to “help repair the world, and because I enjoy inventing new things. I believe civilization owes a massive debt to the world’s inventors and engineers: without their ingenuity, dedication, and hard work we would all have short, miserable lives filled with hardship, poverty, pain, and illness.”

Experience and experimentation come together
Luke Volpe says he was drawn to engineering almost 50 years ago when a distant uncle gave him some career advice. “Back in the days of Sputnik, engineering was a popular and well respected profession, especially in the semiconductor industry, where I was fortunate to work,” he says. Volpe has a BS in Industrial Engineering from Boston University.

His career started at Transitron, a semiconductor company, where he designed crystal-pulling systems and developed photomask processes for semiconductor devices. Almost 30 years ago he went to Dynamics Research Corp., where he is now director of engineering for the Metrigraphics Div., Wilmington, Mass. (drc.com/metrigraphics/metrigraphics.htm). They make extreme resolution microflex (ERMF) circuits, which are used in imaging, monitoring, and coupling devices. The circuits are so small and flexible they can serve in angioplasty devices where they are rolled into a cylinder and placed in veins.

According to Volpe, the ability to produce circuits with traces as small as 5 microns is the result of expertise in three technologies: semiconductor photolithography, thin-film processing, and electrochemical deposition. Volpe says the learning curve was steep. The process consists of spin casting and curing a polyimide base layer. A conductive metal layer is then deposited and delineated into traces. Multiple conductive trace layers are created by depositing a second polyimide dielectric interlayer and forming interconnecting via holes prior to depositing the second layer traces. During the early development stages via holes were formed using a photoimagable polyimide. This process was adequate for circuits with small numbers of via holes but was not reliable for the more complex circuits with three or more trace layers. The problem was solved by using a laser-drilling technique to form the via holes. Reliable six-layer ERMF circuits have been built with this technology. Volpe credits his team with the success of the ERMF circuits.

Ultraclean 3D printing
Z-Corp. figured it would be a great idea to devise a 3D printer that set new standards for ease of use and easy cleanup. Engineering program manager Josh Kinsley and his team including Dmitriy Katalichenko, Diego Torres, Andrew Berlin, Ben Sweet-Block, and Leo Kiefer set out to create one. The result is the ZPrinter 450 color 3D printer which prints parts such as concept mock ups, anatomical models from MRI or CT scans, and automotive prototypes.

On other machines, users had to add powder at the beginning of the process, then brush out the excess powder to get to the finished object. The team worked to automate the powder-handling process but says the task was not easy. “It’s difficult to make powder do what you want it to because it can behave like a solid, liquid, or gas,” says Kinsley. “When you want to move powder around you’d like it to flow like water. But unfortunately it can set up like a solid, and it doesn’t want to go anywhere. Effectively handling powder was one of the major design challenges we faced with the 450, but our automatic powder-handling system worked flawlessly,” he adds.

Kinsley has a degree in mechanical engineering and has worked for seven years at the company in Burlington, Mass. (zcorp.com).