Design and Technology
Radical new medical device designs have prompted radical new
machining and laser processing technologies.
Erik Swain • Contributing Writer
Medical devices are evolving, getting smaller and more complex to meet surgeon and patient needs. As a result, machining and laser processing technology also are
evolving, adjusting to the new designs and material choices that
OEMs need to achieve their products’goals.
Some of the new designs in cardiovascular, orthopedic, neurology and other device disciplines would not have been conceivable as recently as five years ago because there was no way to
manufacture them with existing technology. But machining and
laser processing providers have embraced new ways of manufacturing parts, making these complex products a reality today.
This is incredibly important because these new technologies
are producing annual growth rates in the double digits, or have
the potential to do so, in contrast to legacy products that may provide steady sales but not robust growth.
New technology allows for increasingly smaller and detailed parts. Photo courtesy of Johnson Matthey.
Many of today’s most innovative medical devices have incredibly
precise specifications that only can be executed by equally precise
manufacturing technology. These devices not only require tight
tolerances, miniscule wall thicknesses and odd shapes, they also
require special materials. It’s not as simple as finding a better way
to cut metal.
“Much of what we produce in our machining operation are
critical components incorporated into lifesaving or sustaining devices,” noted John F.X. Morley, product manager, medical, for
Johnson Matthey, a West Chester, Pa.-based provider of numerous
services, including machining and laser processing.“Many of the
‘hottest’devices are starting to combine electrical stimulation with
miniaturization, for instance, devices targeting the deep brain
stimulation, neuromodulation or cochlear implantation. In effect,
these types of devices are applying pacemaker-like technologies to
new areas of the body. The components, therefore, tend to be very
small, manufactured from materials that our customers select on
the basis of biocompatibility, radiopacity and electrical conductivity, and have exacting specifications. Also, our customer base looks
to take advantage of some of the unique properties of precious
metals, either their visibility, electrical conductivity, or resistivity to
corrosion when used in the human body.”
Platinum-based alloys are particularly popular, he said.
“Recently, there has been a push to incorporate many internal
features into the design of the components we manufacture,” he
added.“For instance, think about the challenges of precisely lo-
cating multiple (as many as eight) burr-free, centrally intersecting
through-holes, which run around the circumference of precious
metal tips less than .100 inches in diameter. This has spawned the
need to develop highly precise secondary operations, where the
design of the fixtures necessary to hold the component is just as
critical as the machining operation itself.”
That means the parts must be free of burrs and machined in a
way that little or no force is exerted on to the piece being made.
As a result, according to Morley, companies like Johnson Matthey
are focusing on two technologies that can accomplish that—elec-
trical discharge machining (EDM) and laser machining.
EDM is an erosive process that allows suppliers to make parts
using no force impact.
“Some parts have gotten so small, that if you use any force to