We recently completed an on-on-one interview with editor Alan S. Brown of Mechanical Engineering Magazine and Dr. Hans Langer, EOS Founder and CEO. The result is a Q&A and is attached.

1. MECHANICAL ENGINEERING | JANUARY 2015 | P.20TECH BUZZ || ONE-ON-ONE BY ALAN S. BROWN
Q&A
HANS LANGER
ME: What did you want to do growing up?
H.L: My father was a flight instructor. At 14, I became
a glider pilot, and at 21, the youngest flight instructor
in Germany. It financed my education. I became very
interested in the physics of what makes an airplane fly
or the weather change.
ME: You got your Ph.D. in laser physics in 1980. Why?
H.L: The laser was invented in the 1960s. When I en-
tered university in the early 1970s, we were fascinated
by the future of lasers in medicine or manufacturing.
I wanted to be an expert, and wound up at the Max
Planck Institute. I thought I would go into teaching. I
couldn’t image working for money.
ME: So what happened?
H.L: My advisor said, “There are so many young pro-
fessors and so much opportunity in the laser industry.
If you go there, I think you will be satisfied.” He had
a friend at Carl Baasel Lasertechnik, and I became
employee number 11.
ME: They wanted you to sell, right?
H.L: I was hired to sell to research labs. This was my
home ground. I ran into people who had problems, and
I helped solve them. Sometimes, they wanted to buy
a component. But when I asked what they wanted to
accomplish, it turned out they really needed a different
type of system. I achieved my first-year sales goal in
my first three months.
ME: What got you interested in 3-D printing?
H.L: A U.S. company recruited me to start their Euro-
pean business, and I eventually moved to Boston for
half a year. While there, I visited some labs develop-
ing stereolithography, which used lasers to solidify
photopolymers in chemical solutions. I wondered what
we could do if we could use real materials, such as
metals, ceramics, and engineering polymers.
I started EOS in Germany to pursue that. I found my
lead customer in BMW. When you have a startup, you
need a customer who is willing to pay for development.
We convinced BMW to fund the development of our
first stereolithography system, and later our laser sin-
tering technology for plastic and later metal powders.
ME: What were some of challenges in laser sintering
powder metals?
H.L: I nearly gave up on the dream of making non-
porous metal parts. We needed high laser intensity.
Nothing worked until the introduction of fiber lasers
about 10 years ago. All of a sudden, we could make 100
percent dense materials with no porosity.
We also discovered something we did not expect.
Melting powders with a laser changed their crystalline
structure. It was like laser hardening. We developed
the hardest tool steel you could buy. We replaced a
titanium part in a racing car powertrain that kept
HANS LANGER BEGAN STUDYING LASERS when
they were just emerging from the lab. He founded EOS
GmbH Electro Optical Systems in 1989, and pioneered
the use of lasers to melt and solidify plastic and metal
powders to form complex 3-D structures. Today as
chief executive officer of EOS, he is a leading influ-
ence in the transformation of 3-D printing as a tool for
manufacturing instead of prototyping.
cracking with a stronger laser sintered part.
Suddenly, we had a huge market ahead of us. We had a process that
could optimize part design, strength, and material—and offer superior
properties.
ME: Design is important too, isn’t it?
H.L: Design is the critical factor. For example, cast hip implants weigh
2.25 kilograms. That’s heavy enough to destroy the bones around them,
and eventually patients must replace their implants. When we design
patient-specific optimized implants, they weigh 200 grams and last as
long as three standard implants.
There are a very limited number of applications where we are competi-
tive on cost. Instead, companies are using additive manufacturing to take
big steps forward by redesigning critical parts that combine technologies
and give them an advantage.
ME: Do your customers surprise you?
H.L: I can’t believe what people are doing. Engineers are using advanced
polymers, like PEEK, to replace metal for extreme weight reductions.
We’re moving into the micro world and making parts you can see only
with a magnifying glass. Medical researchers are generating parts they
could not make conventionally. We have lots of playgrounds to play in, and
I am having a lot of fun. ME
Reprinted with permission, Mechanical Engineering magazine
Vol. 137, No. 1, January 2015. Copyright ASME 2015.