Medical Grade Adhesive for Wearable Devices

When designing and manufacturing wearable medical devices, adhesives seem like a simple component. Tapes for skin contact applications are key to producing a successful wearable device. At Polymer Science, our team performs adhesives research and design for skin contact in the medical industry. Our innovations in medical grade adhesive tapes provide quite a few options including adhesives for everyday consumer bandages, repositionable options, short-term wear, advanced wound care and other conditions. Polymer Science works with manufacturers to find the best medical grade adhesives to help your device “stick” to the skin or other substrate.

Get the Performance You Need

Medical grade adhesives are one of the first components to consider in the medical device industry. More specifically, determining the correct adhesive during the development stages of your new product helps to get the performance you need for long-term success.

Considerations of Medical Grade Adhesives

There are many different purposes for an adhesive in a medical device. Whether your product is intended to stick directly to the skin or attach components together or bond the medical device assembly, the functionality of the device falls into the hands of the correct adhesive.

Choosing the wrong adhesive or waiting until the device is already designed to select an adhesive can lead to issues. For example, medical adhesives may interact with the polymers used, the medical device or with other adhesives. These issues can impact the accuracy of monitoring and telemetry devices or the shelf life of medical devices. Adhesives may affect wound healing and wearability for users. The adhesive and release liner systems identified during the design phase of a medical device has a direct impact on manufacturing process efficiency and may prevent negative interactions which leads to costly delays in trials and product launches.

Reducing risk of MARSI

A primary advantage of working with a supplier like Polymer Science for direct skin contact adhesives during the design phase of your new product is accessing additional chemistries and technological improvements. In the case of silicone adhesives and hydrogels, different characteristics like atraumatic removal from the skin help to avoid MARSI (Medical Adhesive Related Skin Injury). In severe cases, MARSI can lead to infection, scarring and prolonged healing. Adhesives can be customized for the most sensitive skin applications.

Improving manufacturing process

Ensuring that the adhesive you’ve chosen will not cause any manufacturing issues is vital to the actual production of your product. Adhesives have many different properties that can potentially slow down the production of your finished device, but determining these from the beginning will save you a lot of time in the long run. You must consider a number of properties including making sure your adhesive isn’t too soft, too tacky, not tacky enough, low adhesion, high adhesion, low shear, too much cold flow and others. The adhesive should be provided in a format that will optimize the process such as in the selection and construction configuration of the liner and support options of the device. These components don’t seem like much in the finished device, but these factors could cause major issues if not taken into consideration early in the product’s development. If an adhesive will be used to bond the device, the adhesive can be customized for rapid curing and adhesion.

Determining the Correct Adhesive for Wearable Device Fixation

At first glance, attaching devices to the skin or bonding components together may seem like an easy choice. Choosing the strongest adhesive possible and covering only the open area of the device is not always the answer. When a device is on a body that is constantly moving, whether that be physical activity or just the compressions of taking a breath, we have to design for those movements. Adding a border around the device instead of confining the adhesive to the open area is an option to provide more stability while also potentially increasing the stability of the device and wear time.

A proper blend of adhesion, tack and shear should be considered during the design of medical devices.

  • Adhesion is the ability of an adhesive to stick to a substrate. In the case of medical grade adhesives, the substrate is typically the skin. Adhesion is important for ensuring that the adhesive stays in place and does not come loose during use.
  • Tack is the ability of an adhesive to form a bond with a substrate immediately after contact. Tack is important for ensuring that the adhesive can be applied quickly and easily.
  • Shear is the force that tries to pull two surfaces apart in a parallel direction. Shear is important to measure the ability of an adhesive to resist being pulled apart.

Finding the ideal balance will be determined by the application. Stick-to-skin applications’ success is determined by the adherence of the device to the skin over a certain period of time. In terms of direct skin contact, choosing the wrong adhesive is problematic. If medical grade adhesives do not have the properties to stick to the skin long enough or fall off the skin before the device can do its job, the accuracy of the data generated, if any, will be compromised.

The same can be said at the other end of the spectrum with an adhesive that is too aggressive. Medical devices that are only meant to be worn for a short period of time can cause extensive trauma (MARSI) to the skin with adhesive strength that is too strong.

You must also take into consideration the skin itself. Skin is the body’s largest organ so taking care of your skin is vital to your health. The skin as a substrate provides many challenges based on its characteristics and the environment where the medical device will be used. When choosing the skin applications consider:

  • Living tissue including skin is in a state of constant change and regeneration. Temperature, moisture, cell growth and cell death impact the effectiveness of an adhesive.
  • Variation of skin surface from person to person and locations on the body. The wearable device must adhere to hairy, oily, dry, wrinkly, stretched and smooth skin.
  • Skin is subjected to shear even in daily activities. Clothing rubbing and limb movement will test the adhesive.
  • Environmental exposure including natural changes in humidity and cold and heat should be accounted for. Contaminants on the skin’s surface include precipitation, sweat, lotion and other foreign sources.
  • Skin condition varies with age and medical issues. Wounds, abrasions and sensitive skin all help inform the most suitable adhesive.

Common Questions for Wearable Manufacturers

Despite some of these more challenging skin characteristics, medical grade adhesive technology has made it possible for you to wear a device to track and monitor almost anything. The key is working with a team of experts to supply the best medical grade adhesive for your new product. When you contact Polymer Science, there are some common questions.

Asking some of the questions below will help you in deciding which adhesive will work best for your product:

Who is my target market? Who will be wearing my device?

Understanding more about the end user and the target market helps to plan for the potential environmental challenges and skin characteristics. If a wearable device is likely to be used with fragile or sensitive skin types, the design may require specialized atraumatic adhesives. Silicone adhesives and hydrogels may be the preferred medical adhesive in these situations. Within these adhesives, there are additional design changes and customization processes.

Does my device design utilize adhesives with no direct contact with the skin?

Not all of the potential adhesives in a medical wearable device are skin contact adhesives. Conductive pressure sensitive adhesives (PSAs) are often used on the “device side” of the application as a bonding, or connecting component. These adhesives should be considered when choosing the skin contact component to avoid any potential material incompatibility issues. Double-sided medical tapes, bilaminates and trilaminates can be constructed with different adhesive coatings and carriers. The device side may need an aggressive adhesive whereas the preferred skin contact adhesive needs to be repositionable. Working with experienced suppliers helps to identify the perfect solution.

Where on the body will my device be located?

Medical wearable devices for fitness and activity tracking may be showcased like a wristwatch. A large number of people who are wearing medical devices to treat and/or monitor a medical condition prefer privacy. These people may not want to broadcast or draw attention to their condition, therefore warranting a smaller, more discreet device that can easily be hidden. The best medical grade adhesives suit the end user.

How long does my device need to be worn?

Short-term and long-term wear can lead down specific adhesive paths. Knowing the intended use of the device can help narrow down which adhesive path makes sense for your product.

What is the area and shape of my device?

Determining the shape of a product can appeal to sales and marketing but when an adhesive is involved, shape plays a big role in performance. A device with square corners, for example, can fall off more quickly from a shirt rubbing or friction from movement than a product with rounded corners. The adhesive area may impact the weight-bearing aspect of a device which ultimately impacts the wear time of the device.

Does my device need to be repositioned?

Each adhesive system has a unique set of characteristics and is not one size fits all. The repositionability of a hydrogel or acrylic PSA is not going to be the same as that of a silicone gel. Learning those requirements up front helps in choosing the best adhesive for the finished device. If the end user will take the device off and move it somewhere else on the body, the adhesive must suit this requirement.

Will my device need to be sterilized?

If the device needs to be sterilized, the type of sterilization can affect a range of factors. Sterilization methods vary depending upon not only the adhesive itself, but also on the other components of the device. For example, if you are designing a product that requires gamma sterilization, with the current available adhesive systems, silicone gel adhesives wouldn’t be an option for your device. Some devices undergo multiple sterilization cycles which should also be considered.

What environmental factors will my device be exposed to?

The environment can impact the performance of an adhesive. Just as in medical device assembly, the temperature, humidity, weather and other factors affect the reliability of the adhesive and the viability of the product. Wearables must stay in place and perform no matter what changes with the skin’s surface or the outside environment. This leads to a few additional FAQs:

  • Is this device meant for rigorous physical activity?
  • Is this device going to be exposed to water or perspiration?
  • Is this device going to be worn in extremely cold or extremely hot environments?
  • Are there any other factors or contaminants that could compromise my product’s integrity like lotion or other skin care products?

Working with Polymer Science

Work with a supplier that understands your form, fit and functional requirements and provides compatible options for your exact problem. Polymer Science has extensive material knowledge that will save you a lot of time in the research and development phase of your application. Polymer Science is committed to providing you with today’s most innovative skin contact adhesives for the medical industry. Our diverse team of highly skilled engineers and technical staff, in conjunction with our state-of-the-art equipment, provide you with a quality product that is consistent with your application requirements. Our design team works quickly to provide the solutions you need, allowing your project to expeditiously move from conception to commercialization, giving you the edge to ensure your next project is a success.

Polymer Science offers P-DERM® skin contact adhesives ranging from conventional acrylics and medical grade adhesives to our innovative atraumatic, pain-free removal silicone gel and hydrogel adhesives. Our coated materials are specifically formulated and fabricated to meet the technological challenges in the medical industry today with a range of different characteristics to meet the requirements of your application. All P-DERM® skin contact adhesives are made in the USA.