Adhesive innovations minimize design engineering challenges

Features - Adhesives

Designing user-friendly stick-to-skin devices for diabetic patients requires knowedge of skin, correct adhesive material, and holding strength.

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January 30, 2020

PHOTO COURTESY OF 3M
Skin is a tricky substrate, making the wearable device design process notoriously challenging. The skin of diabetic patients requires even greater attention, as the condition often leads to loss of elasticity, dryness, thickening, and increased susceptibility to infection. Adhesive technology innovations can minimize challenges associated with diabetic devices, such as continuous glucose monitors (CGMs), insulin pumps, blood glucose test strips, and other diabetic devices. Whether sticking a device to skin or adhering components together, adhesives help solve design challenges, prevent skin injuries, and ensure devices work as intended. To develop wearables for diabetes management, designers must know how skin of patients with diabetes can differ from those without the condition.

Diabetes’ effects on skin

Skin moves, breathes, expels moisture, and completely regenerates itself about every two weeks. It’s largely made up of water and helps regulate body temperature. It’s an indicator of health, protecting against infection and other external dangers, and reflects what’s happening inside our bodies. If we’re too hot, it sweats. If we’re allergic to something, our skin can break out in a rash.

For patients with diabetes, excess blood glucose can combine with skin, stiffening blood vessels’ walls. The skin’s response to external stimuli deteriorates, it doesn’t get as much oxygen, and it can eventually lose its sensory nerve cells, meaning it won’t feel pain. Injuries become more likely to go undetected, compromising skin and increasing the risk of infection for patients whose condition already weakens the immune system.

Diabetic skin can also lose its sweat gland function, leading to xerosis (dry skin), which can cause itchy, thickening skin. Other ways diabetes can alter skin is from aging and sun exposure damage, making skin less resilient and elastic, further deepening fine lines into wrinkles. Abnormal glucose metabolism can exacerbate these changes.

Improving designs of diabetes management devices

Thoughtful adhesive selection can solve tough design challenges.

Adhesives can promote skin health – Devices such as CGMs can heighten the risk of infection. However, selecting the right adhesive for each application helps skin maintain its integrity and ensures the device stays adhered for its intended duration, minimizing infection risks.

PHOTO COURTESY OF 3M

Extended-wear, pressure-sensitive adhesives are a skin-friendly option for compromised skin. Choose a gentle one to limit further irritation. Silicone and some acrylic adhesives may be best.

  • Silicone adhesives: Optimal gentleness for fragile, sensitive skin; conforms to skin upon application; less painful removal; moderate breathability formulated for short-term application
  • Acrylic adhesives: Breathability, biocompatibility – essential for adherence for more than several days; can be formulated to be aggressive if longer adherence is necessary

Adhesives can promote device integrity – The right adhesion strength and durability ensures a device stays intact. The adhesive may still need to be biocompatible if it comes into contact with skin, but it doesn’t need to be gentle or skin-friendly.

Many materials are considered in designing blood glucose test strips, but one of the most important is adhesive. Adhesive must be compatible with the hydrophilic materials that promote fluid flow, because these two components are important to the strip’s accuracy. When they don’t function together, and in combination with the other layers’ materials, trouble can arise during test strip design, manufacturing, and shelf life.

Think beyond adhesives – Proper adhesive selection can mitigate many challenges but won’t prevent every potential issue. For instance, an adhesive can help prevent devices from falling off prematurely, but if the device gets knocked by a door, adhesive strength can only do so much. To help prevent premature fall-off – and to enable seamless integration into a patient’s everyday life – slim profiles ensure the device stays close to the body and rounded edges can help prevent it from getting caught on items, such as clothing.

From microfluidic applications to adhering blood glucose test strip’s layers together, adhesives help maintain skin health and device integrity.

Clear instructions for use (IFUs) with diagrams and video tutorials on how to operate, apply, and remove devices are also needed. Include tips such as applying the device to a different area of skin at each use to allow skin to regenerate and maintain its health.

Diabetes management is time-consuming and emotionally taxing, and patients deserve thoughtfully constructed devices to help them make critical health decisions with little negative impact to their lives. Design engineers who partner with a materials supplier well-versed in creating devices for diabetes management can guide you through the process, helping alleviate some of the pressures and enabling better outcomes.

3M

About the author: Del R. Lawson, Ph.D. has more than 25 years of experience at 3M in laboratory management, strategic product platform creation, and Lean Six Sigma operations. He currently leads Medical Materials & Technologies new product development and commercialization efforts in 3M’s Medical Solutions Division.