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Prickly Situation continued
in-vivo imaging and other potential
biotech applications—into the skin
using microneedles made via 2PP.
(The procedure is aimed at diagnosing
and treating skin cancer.)
Microneedles fabricated using 2PP,
he explained, create pores in the
15µm-thick stratum-corneum layer
of the skin. The needles are hollow
or “mosquito fascicle-shaped …
created out of organically modified
ceramic materials,” he said.
The devices were tested on
pig skin and allowed delivery of
quantum dots to the deep epidermis
within 15 minutes, Narayan said. By
comparison, “topically applied carboxyl
quantum dots remained on the topmost
50μm of the skin and demonstrated poor
penetration.”
Narayan believes the new 2PP process
is best-suited to mass fabrication. That’s
DOWNsizing
continued from page 19
study published in the April 25 issue
of the Journal of the American Medical
Association showed that cardiacdevice
infective endocarditis (CDIE)
increased 210 percent from 1993 to
2008. Of the 177 patients enrolled in
the study who developed CDIE, nearly
a quarter of them died as a result.
“The high rates of mortality emphasize
the need for improved preventive
measures,” the study concluded. “Given
that the number of cardiovascular
implantable electronic devices placed
are increasing rapidly, further studies
on the prevention and treatment of this
serious complication are needed.”
As it turns out, silicon technology
once again may be the key to safer,
much smaller and less costly pacemakers
by making it possible to
eliminate the lead wires that run from
the device to the heart.
Minneapolis-based Medtronic Inc.’s
Dr. Stephen Oesterle, senior vice president
for medicine and technology,
can readily be found on YouTube
discussing a pill-size pacemaker that
could be inserted into the heart via
40 | MAY/JUNE 2012 | MICROmanufacturing
Laser Zentrum Hannover
Microneedles fabricated via multifocus, two-photon
polymerization.
because it can be used to process a variety
of photosensitive materials, including
acrylate-based polymers, organically
modified ceramic materials, zirconium
sol-gels and titanium-containing hybrid
materials. “Many of these materials are
widely available and may be obtained at
This illustration, based on Medtronic's
online presentation, depicts the size and
shape of a pacemaker sitting atop a penny.
Currently under development, the device
will eliminate the need for lead wires.
a catheter and attached directly to
the wall of the heart. Such a device,
Oesterle told a health technology
conference in 2010, is just 3 to 4 years
away from being introduced to the
market.
What’s more, Medtronic is working
on an even smaller pacemaker, which
would be close to the size of a grain of
rice. The technology for such a device
low cost,” he said.
Gittard said mass replication can be
achieved through creation of a master
structure that serves as a mold. He and
an unnamed industry partner are working
to perfect the process.
While microneedle technology is still
developing, the needles themselves are
not the end goal, according to Radspinner.
They are simply the most logical, most
efficient method of delivering FluGen’s
product—a flu vaccine for seniors. “This
is a way to enhance the efficacy of vaccine
delivery,” Radspinner said. “That’s what
microneedles are to us.” µ
About the author:
Howard Lovy writes
about science,
technology and
innovation. He is based
in Traverse City, Mich.
Telephone: (231) 620-
2730. E-mail: howardlovy@gmail.com.
already exists, Oesterle explained,
citing through-silicon vias, integrated
recharge and telemetry coils, a 3-axis
accelerometer, die-stack assembly and
wafer-to-wafer bonding.
By using key technologies such as
micro laser drilling or DRIE (deepreactive-ion-etching)
to produce
through-silicon vias and enable 3-D
packaging, there doesn’t seem to be
much standing in the way of such
development. Except, of course,
coming up with a power source for the
tiny device.
“The hard part is [developing]
batteries that last,” Oesterle said, anticipating
that the ultimate solution
may be some sort of thin-film battery
technology or possibly an energyharvesting
component.
Though Medtronic representatives
would not comment on the progress
of either pacemaker, the company did
confirm that both projects remain
under development. µ
About the author: Dennis
Spaeth is electronic media editor for
MICROmanufacturing. Telephone: (847)
714-0176. E-mail: dspaeth@jwr.com.