“Flexcon as a company has been focused on the graphics and labels business for 60 years. Now we see a core capability that we have in coating adhesives on films that can be used in a different way,” Shaun McDonough, medical market development specialist at Flexcon, told Medical Design & Outsourcing earlier this year.
Flexcon, for example, has been touting its Dermaflex product line, which features biocompatible adhesives that are ISO 10993 and certified for safe skin contact. Dermaflex’s potential applications include electrodes, surgical drapes, medical tapes, medical drapes and diagnostic components.
The top challenge when it comes to adhesives and wearables is that skin is such a tough substrate compared with, say, a wall or a car, according to McDonough.
“Skin is so different,” McDonough said. “It’s ever-changing. It’s continually regenerating, dying, sloughing off, sweating, having oil coming out of the pores.”
Also, add in the elasticity of skin and the constant movement of the human body.
“If you don’t have not only the right adhesive but also the right film to go with the adhesive, you’re setting up your application for failure,” McDonough said. “You need adhesive and film construction that’s going to match the elasticity of the skin but also robust enough that it’s not going to peel off at the first sign of picking.”
It’s also a fine line between creating a lasting bond on the skin and causing skin damage. Picking a film that’s conformable and that can stretch increases the odds that the adhesive will stick.
The industry standard for Flexcon and other adhesives providers is to test an adhesive’s strength on stainless steel, since skin is so variable between people. High- and low-density polyethylene are also used for testing, but it’s still not necessarily the real-world feel.
“It’s a constant battle within the industry to find the right testing method to reflect the wearability the length of time, the strength of the adhesive on someone’s skin,” McDonough said.