7 ways adhesives can cause medical device failure

When adhesives are not thoughtfully considered and optimally designed into the device, the consequences can wreak havoc throughout the development and launch process. To help ensure your device has a bright future, rethink these seven areas:

1. Skin isn’t like other substrates

Many substrates within the medical device world are static, such as metals and plastics. Past performance can anticipate how they’ll react under new circumstances.

Working with skin is more nuanced. Skin is an evolving organ. It’s a living, breathing entity with critical functions that contribute to keeping us healthy and safe. Skin grows hair, produces oil, releases moisture, and moves and flexes with the rest of the body. It’s one of the first defenses against infection and helps regulate body temperature. It changes as we age and our health status evolves.

When designing a device to adhere to skin, understand the end-users’ skin and how their health, environment, and age affects it.

2. Environmental conditions

Environmental conditions are important at three different times in the device’s lifespan:  where it is manufactured, stored, and used. The device’s adhesive must perform independently of where the device is throughout its life.

If the device will be exposed to extreme temperatures or hostile environments, pay attention to adhesives’ thermal-transition properties and moisture levels. Moisture can degrade materials, with paper-based and hydrophilic films being more susceptible.

3. Material combinations, potential interference with device accuracy, reliability

Incompatible material combinations can force medical devices to fall apart prematurely, perform unexpectedly, or suffer integrity issues. Compatibility is determined by each layer’s mechanical and chemical properties. How are the properties the same? How are they different?

Identify potential sources of contamination from one layer to the next and determine if the sources exist naturally or are triggered through manufacturing, sterilization, or another assembly step.

Decide what characteristics the adhesive will exhibit early in development.

4. Device design testing

Assembling a cross-functional team sets up successful clinical testing. Each team member will bring expertise, perspectives, and experiences to the trial device design, helping to create the best device possible.

Clinical testing simulates the device’s real-world intended use. The team determines the best ways to apply and remove the device, stretching and conforming the adhesive for optimized wear time. It can help anticipate pitfalls and sidestep them before they happen.

Clinicians, materials specialists, manufacturing experts, regulatory affairs professionals, and mentors can provide invaluable experience and guidance by providing unique perspectives.

5. Manufacturing

When scale-up to manufacturing is overlooked, unforeseen issues can pop up after it’s too late to make cost- effective changes.

Use the same materials in the prototype as the final device and run multiple lots of production-equivalent material. Using the same materials will help you understand how they’ll react to and perform during manufacturing. The chosen adhesive needs to withstand the speeds, tensions, and friction it’ll encounter during manufacturing. If it can’t, the adhesive could break or fail at a time when structural changes would be cost prohibitive.

Running multiple lots will help you understand if materials can be processed repeatedly. If an adhesive is too soft, it can gum up equipment during production and conversion, halting a fast-paced line, potentially adding unforeseen costs and unexpected downtime.

6. Sterilization process

Design the sterilization process to meet the device’s needs. It’s important to consider all device components, materials, temperatures, duration, and packaging sterility.

Some sterilization methods can impair certain materials. Even if the original material does not pose an issue before sterilization, it could unintentionally interact with other materials and cause problems. Gamma radiation often causes polypropylenes to stiffen and degrade.

7. Scalability

Design for manufacturability, design for scalability. The device, its components, and the manufacturing process take time and can add complexity to scalability. It’s important if there’s unexpected market demand or an internal desire to produce high volumes of the product cost-effectively.

Map a clear manufacturing path from the beginning and keep these three main stages in mind:

When materials and individual components are joined to create a working prototype. The product’s robustness, including sensitivity, selectivity, specificity, and reproducibility, is evaluated then compared to laboratory performance. It’ll inform whether design improvements are necessary to mitigate any design or manufacturing issues.

Use high-speed replication processes, including critical design parameters, to produce the desired batch or volume of devices. Using these real-world processes will illuminate problem areas and changes to make.

Produce the volume of devices needed to meet forecasted annual demand.

Something to stick with you

We have worked with medical device companies and engineers for many years, and one of the most important insights is: if someone experiences pain, device failure, or discomfort, they won’t use or recommend your product.

Your device’s destiny is in your hands. Thinking through every material, component, and process and how they all interact may be more work upfront but it’ll help you navigate every decision. When in doubt, find a mentor and consult your adhesives supplier.

About the author: Del R Lawson, Ph.D., is the R&D manager in 3M’s Medical Solutions Division and can be reached at 800.584.2787.

3M: https://3M.com/medtech