Material Spotlight: 3M Medical Tape 4576 Long-Term Stick-to-Skin Adhesive
3M™ Launches New Long-Term Wear Skin Contact Adhesive
From products that help prevent infection, hold an IV in place, attach electrodes, and a variety of other medical applications, 3M™ has been sticking things to skin for around 55 years. However, most of those products are only designed to hold anywhere from a few hours to a few days. Wearable medical devices such as continuous glucose monitors, drug delivery systems, and more require a new type of adhesive that can remain on the skin for an extended period of time. We recently spoke with Audrey Sherman, Division Scientist, 3M™ Medical Solutions Division and Del Lawson, Medical Materials & Technologies Laboratory Manager, 3M™ Medical Solutions Division to discuss the development of their new extended wear medical tape.
Stick-to-Skin Adhesives - Demand for Longer Wear Duration
3M™ offers several products that meet a 10-14 day wear duration including, 4075, 4076, and 4077. However, they recognized the wearables market is rapidly moving towards even longer wear times, and set out to meet the need for a stick-to-skin adhesive that stayed in place beyond the 10-14 days of their existing product line. “We had to go back to the drawing board and completely start over. We went all in on a particular set of formulations with some great science behind it, and feel confident that this new product meets the needs of customers currently and into the next generation of products,” said Lawson.
Introducing 3M™ Spunlace Extended Wear Adhesive Tape on Liner, 4576
3M™ Extended Wear Adhesive Tape 4576: Development Hurdles
3M™ faced three major hurdles during the development of their new extended wear adhesive, 3M™ Spunlace Extended Wear Adhesive Tape on Liner, 4576:
1 - Into the Unknown
Developing an adhesive that would stick to skin for longer than 14 days was uncharted territory for 3M™. Scientists wondered if it was even possible. Asking themselves questions like how far can we push wear duration? What happens when you are keep something on the skin for that long? “We had to find a formulation that would have enough adhesive to grip and hang on for up to 21-days yet remove cleanly and not leave any adverse effects on the user,” said Sherman.
2 - Meeting Expected Wear Duration
It is critical that the adhesive will stay bonded for the expected wear duration. Medical devices are not something that you pick up at the drug store. They require a prescription. If the medical device doesn’t stick for number of days that the doctor, pharmacist, and device maker propose, it is like standing at the sink and dropping half a bottle of pills down the drain. Just like running out of pills, if the device pops off early patients are left in a bind trying to figure how to manage the gap before they can get a refill.
3 - A Global Crisis
An atypical development hurdle encountered was the COVID-19 pandemic. Attempting to develop an extended wear skin-contact adhesive without trying it on healthy human skin was challenging. “During the height of the pandemic, we were unable to even be in a laboratory together much less get clinicians and subjects together to test on humans. So, we did extensive bench testing in the laboratory to try and sort out what would happen and offer some predictability of results once human testing began,” said Sherman.
Skin Contact Adhesive Challenges
The skin is unlike any other substrate. Skin contact adhesives must be able to move and flex with body, withstand moisture and sweat, and do no harm when removed. End-user demographics such as age, race, gender, body type, body hair, activity level, and patient health can all impact material selection and adhesive performance.
“We have to be very careful about the ingredients that go into these products. We do a lot of compatibility testing to make sure we don’t cause any adverse or allergic reactions. It is important to test around the world and at various times of the year. Geography, climate, and genetics all play a large role in skin properties,” said Lawson.
Wear performance also depends on the design of the device, including its size, weight, and rigidity. “We are not yet into flexible electronics that bend and move like skin. Since most wearable devices are still rigid, you need to rely on the layer between the skin and the device to hold and absorb that stress. It is a gradient of stress from the skin all the way up to the rigid wearable device. If you don’t take that into account, the device can pop or lift off leading to device failure. You need an adhesive skirt that sticks out beyond the edge of the device to help manage that stress,” said Sherman.
Stick-to-Skin Adhesives: Back to Basics
3M™ went back to basics on pressure sensitive adhesives to push past the current 10-14 day wear limitations. 55 years of science and innovation gave them a strong foundation to build upon. “We know a lot about how to manipulate adhesives on different substrates. I like to say that in the laboratory we torture polymers. We do this to make sure that when we get to the skin we have an adhesive that meets the required wear duration without causing trauma when removed,” said Sherman.
Each layer of a wearable device has to function together as a cohesive unit. Individual layers can interact with each other and impact performance. The best way to learn how materials perform is through prototype and testing. Building early concepts and put them through rigorous testing to ensure you do not encounter unforeseen interactions or unintended consequences that might cause adverse skin reactions. “Design engineers have to be paranoid and think of all the different things that can go wrong so that you can test and ensure that nothing was missed,” said Lawson.
Pushing the Limits: 21-Day Wear Duration
After all the research, innovation, and testing, 3M™ introduced their Spunlace Extended Wear Adhesive Tape on Liner, 4576. 3M™ 4576 is an acrylate-based adhesive that provides excellent adhesion to skin while remaining flexible and conformable.
Per 3M™, here are some suggested applications:
- Extended wear medical and retail applications requiring secure attachment to skin up to 21 days
- Can be used for attaching finished device to skin
- Excellent adhesion to low surface energy materials
- Material and / or technology for health care, retail or medical device construction
Beyond 21 Days: Is it Possible?
“People often ask us how far can wear duration be extended. I don’t think we know yet. Every 14 days your skin replenishes itself and a new layer rises to the top, so it is logical to assume there is some type of limit there. It really comes down to how long you can have something on the skin that continues to meet the do no harm criteria. So, I don’t think we are willing to say there is a limit yet. There probably will be one at some point, but we will continue to push that boundary,” said Lawson.
Converting Concepts into Reality - From Roll Goods to Finished Parts
Long-term wearable medical devices rely on pressure-sensitive tapes to both hold the device together and stick to the skin of the patient. While most of these tapes are available in basic roll form, that is rarely the form they need to take for use with the end customer. That’s where a flexible materials converter like JBC Technologies comes in.
JBC and other converters transform rolls of materials into finished parts that help our customers bring their products to fruition. Using our myriad of vertically integrated converting and high-speed rotary die cutting processes, JBC can laminate diverse materials together, slit to custom widths, island place, gap parts, cut specific shapes, and present your part in the way that best suits your finished device requirements and production environment.
In fact, one of the most energizing aspects of the converting business is that there are almost limitless possibilities to what we can fabricate. With thousands of different materials at our disposal and so many different converting processes, the phrase “limitless realities” is not just hyperbole.
Here are four ways a flexible materials converter can help:
- Rapid Prototyping: Get help pairing adhesives with foams, felts, flocks, nonwovens, films or foils. Test several materials for the same part as well as, perform fit, form, and function tests.
- High Quality, High Volume Production: Produce parts quickly and cost-effectively with converting services such as rotary die-cutting, flatbed die-cutting, and lamination.
- Optimized Part Presentation: Save time and eliminate inefficiencies with part optimization processes including Kiss-Cut, Butt Cut, Island Placement, Through Cut, and Pull Tabs.
- Fewer Resource Constraints: Maximize financial and human resources by outsourcing to a converter who can utilize the best equipment and highly skilled operators for each application.
Check out our blog Four Benefits of Working with a Flexible Materials Converter to learn more.
JBC + 3M™ = Value-Added Solutions
As a 3M Preferred Converter, JBC works closely with 3M to help us navigate the ins and outs of the science of skin. Assistance with adhesive selection is just one of the many value-added solutions that JBC offers to help our customers improve quality, reduce costs, and increase efficiency. Our engineers and technicians have over a century of combined expertise in material selection and product design knowledge. Contact us today to learn more about how our custom solutions can help you convert your design concepts into reality.