One of the most important steps in designing a medical wearable is skin-contact material selection. There are number of common skin-contact PSAs that all perform best in different situations, so how do you choose the best for your application?
Marian collaborates with a variety of material suppliers to deliver high-performance PSAs that will be worn on the body for a period of time. As a trusted supplier partner of Marian and a global leader in medical tapes and adhesives, including skin-contact materials, Avery Dennison® brings rigorous testing protocols and extensive material expertise to every medical project.
Understanding that adhesive selection for a wearable application is complex and to help simplify this process as much as possible, Avery has developed and defined protocol for conducting wear studies. These wear studies allow for side-by-side comparison of wearable adhesives among other benefits to help make sure you feel confident in your skin-contact PSA.
What is a Wear Study?
A wear study is a controlled evaluation that tests how medical adhesives and wearable devices perform on human skin over time. These studies are essential for three key reasons:
- Patient satisfaction: Ensuring comfort, wearability, and ease of removability
- Product longevity: Confirming wear performance, especially for extended wear products
- Manufacturing efficiency: Preventing costly delays by identifying issues early
By conducting wear studies, you can confidently develop wearable medical devices that meet critical performance criteria including longer wear time, enhanced comfort, and atraumatic removal.
The Benefits of Wear Studies for Wearable Adhesive Selection
Well-designed wear studies offer significant testing flexibility. When including control groups, you can isolate specific variables. For example, you can evaluate a new adhesive against established benchmarks or another competitive material. Multiple hypotheses can also be tested concurrently by applying different adhesives simultaneously, maximizing data collection efficiency.
Lab tests can measure adhesive strength, but they can't fully predict real-world performance. Human skin varies greatly from person to person, differing by factors including:
- Age and skin condition
- Body temperature and perspiration
- Environmental humidity
- Wear duration requirements
- Placement location on the body
Three adhesives with slightly different formulations. Multiple different adhesives can be tested on the same subject concurrently.
While Avery Dennison maintains rigorous standard tests for these variables, synthetic substrates fall short of replicating actual human skin. For accurate and clinically relevant data on differing skin types, human test subjects are nearly always required.
Wear studies also provide insights that laboratory testing cannot. Human participants can offer feedback on:
- Aesthetic appearance: Does the adhesive look acceptable to the subjects?
- Residue management: Is the skin clean after removal?
- Comfort and irritation: Does the adhesive cause redness, itching, or discomfort, or is it painful to remove?
These subjective factors are also critical for product acceptance and long-term patient compliance.
The Challenge of Wear Studies
Despite these benefits, executing a wear study isn't simple. Designing protocols, recruiting participants, and managing the testing process requires significant time and expertise. This is where having a structured approach, like Avery Dennison's wear study protocol checklist, makes a huge difference.
Avery Dennison’s 8-Step Wear Study Protocol
Avery Dennison created a structured, 8-step protocol their teams follow when conducting a wear study to ensure a consistent, repeatable process. This checklist covers study design, participant selection, execution, and reporting, ensuring designers evaluate adhesion, durability, device performance, and user comfort effectively.
Steps 1-4 focus on preparation: defining objectives, establishing criteria, and protocol training.
Steps 5-8 cover execution: recruiting participants, conducting the study, collecting data, and analyzing results.
This protocol takes the guesswork out of wear study design, helping make data-driven decisions about adhesive selection and product development.
Download Avery's wear study protocol checklist here!
Avery Dennison Internal Wear Study Protocol Checklist
Adhesive Selection
One of the costliest mistakes in medical device development is waiting too long to select an adhesive. Adhesive selection should happen early in the design process, and this timing is absolutely critical for medical devices.
Medical products, especially those meant to be worn on the human body, typically take years to reach the market and require extensive testing and regulatory compliance. Delaying adhesive selection creates significant risk. If issues surface during testing, the product's entire timeline can be disrupted. Last-minute decisions often result in settling for off-the-shelf materials rather than optimized adhesives specifically tested and engineered for the application.
Early selection and thorough testing prevent problems that are much more expensive to fix later. Discovering issues after product launch, like poor adhesion, skin irritation, or excess residue, can lead to patient dissatisfaction, costly recalls, and/or product redesigns. Switching adhesives late in development or post-launch is a costly mistake in terms of both time and money.
Skin contact adhesives aren't the only consideration. Most medical devices rely on structural adhesives to bond internal layers and components. While these adhesives typically aren't evaluated in wear studies, they have their own performance requirements based on the device's design, so it’s also crucial to keep them in mind early in the design process. Marian Sales Engineers will work closely with you to learn more about the specifics of your application to make sure you're considering the right adhesives.
Let's Talk About Your Project! Whether you're developing a new medical device or updating an existing one, Marian's engineering teams can help you navigate adhesive selection, work with Avery Dennison to conduct wear studies, and bring your product to market faster. Contact us today to get started!
