Sean Fenske, Editor-in-Chief
Adhesives in the medical device space refer to a variety of different ypes of technologies. While they all involve the bonding of two substrates, the actual applications vary greatly. With medical device
adhesives, bonding can be achieved for two dissimilar materials in the manufacture of a device, bonding a wound care product to a patient’s skin, or even
bonding together a surgical opening following a procedure. In this roundtable
presentation, the first two areas of application were the focus, with participants discussing the use of adhesives for manufacture and wound care.
When it comes to materials for a project, medical device designers typically
have certain characteristics or properties they are seeking to suit their requirements. In the area of adhesives, this may include flexibility, regulatory compliance, environmental factors, and cure time. However, as with any component,
there are potential aspects that are overlooked or a benefit exists of which the
designers are not even aware.
In the area of adhesives for manufacturing, Alexandra Kiniry, Global Market Development Manager for Medical at
the Henkel Corporation ( www.henkelna.com) offered two
properties that aren’t always considered by engineers. “In a
market heavily regulated by the FDA, process control is of
utmost importance to the medical manufacturer,” she said.
“The dispensing of single component adhesives can be
easily automated with the use of valves. Precision drops
or beads can be dispensed with these systems, and automated controls can
be implemented to confirm the exact amount was dispensed each time.
Adhesive detection can be automated when fluorescence is formulated into
She continued with insight on a second consideration – risk mitigation.
“The medical device industry is constantly trying to mitigate risk, specifically
in the area of supply. Due to the long validation process and strict FDA reg-
ulations, device manufacturers have to avoid any changes once a production
process is in place. Therefore they frown on any supply interruptions from
their suppliers.” She explained that it is best to ensure a supplier can offer the
same adhesive from multiple locations and has contingency
plans in case of natural disaster.
Norm Riley, Technical Marketing Director at Applied
Silicone Corporation ( www.appliedsilicone.com), offered his
own thoughts on the topic. “Many of the modern engineered
plastics, elastomers, and alloyed metals that are the foundation of today’s design advances are in need of practical
Bonding Can Present
a Sticky Situation
bonding/joining technologies. Current adhesive solutions for medical
device manufacturing often require expensive surface treatments or modi-
fications as a secondary process performed by a contractor. Medical device
designers and manufacturers seek to maintain control and traceability
throughout their manufacturing process so companies would benefit from
the addition of a silicone bond and thereby simplify or eliminate the need
for secondary processing.”
Ravi Ramjit, Ph.D., VP of R&D at EuroMed (www.euro-
medinc.com), provided insight on the wound care sector.
“Rheological properties of adhesives give an indication
as to their wear time. It is a property often overlooked
by designers and manufacturers, as it rarely shows on a
specification sheet. Rather, designers and manufacturers are
most often familiar with tack or probe tack testing results
on stainless steel. Although an indicator of short-term tack,
these results do not have a direct correlation with the length of time an
adhesive stays on skin.”
Some of the most interesting innovation in the medical adhesives space
is happening in the wound care sector. The spotlight is currently shining
brightly on 100% solids technology. While still only offered by a limited
number of suppliers due to the investment required, this type of adhesive
provides clear benefits for device
makers in this space.
“Solids technology at 100% eliminates volatile and sometimes harsh
solvents [that] require venting permits
and EPA regulations,” said Dr. Ramjit.
“Also, some of the solvents used may
not be the most biocompatible on skin
depending on the ppms left.”
Riley added, “Adhesives con-
taining no solvents or carriers can
reduce the cost of manufacturing
by simplifying the application
process, reducing waste streams,
and eliminating harmful emissions.”
Wound care is not the only area experiencing innovation, however. In more
traditional bonding applications, enabling the use of flexible adhesives for
medical device manufacturers can bring benefits for a project.
“Light cure acrylics are most commonly used in medical device assembly Norm Riley
Automated dispense of light cure
acrylic adhesive. (Credit: Henkel)