Painless Medical Tape

A research team at the Brigham and Women's (BWH) hospital recently created a new type of medical tape that can be removed from skin without pain. Medical tapes before this invention were very secure in terms of adhesion properties, but they damaged skin when being peeled. Current medical tapes have a lot of backing and support that allows it to stick strongly on a patient. However, when taken off, the tape used leaves some of the adhesive material on the skin. Although this does not affect all skin types, neonate skin, which is newer and more recently grown, does face more serious damage. 

Painless medical tape

The new medical tape created has three-layers which retains the strong adhesion properties of previous tape, but also adds a feature that allows the tape to be easily peeled off. There is one layer of tape that serves as the adhesive layer and another layer that serves as the backing support. A final layer exists in between these two, referred to as the anisotropic adhesive interface. The anisotropic feature means that the layer's physical properties depend on direction, opposed to an isotropic feature, which would refer to the properties of materials that are the same in all direction. For example, wood has anisotropic properties, containing lines that go in one direction. The wood contains more strength when the lines all go in one direction, causing wood to have anisotropic properties. 

Anisotropic features have advantages, being stronger in a certain direction. The scientists from BWH used laser etching and a release liner in order to make the anisotropic layer of the medical tape. This feature allows the medical tape to have a much higher shear strength as it is now dependent on direction. The release liner allows for the medical tape to be removed with little force. Solving the previous issue, if any adhesive remains of the skin, it can be gently rolled off using a finger. In other words, the medical tape would come off skin more easily. Release liners work by using silicone releasing agents, which have a low surface tension of wetting. Wetting refers to the characteristic of how a liquid deposited on another liquid or on a solid spreads out. Because silicone, a key component of release liners, has a low surface tension energy, it does not spread too much when on another layer of the medical tape and, ultimately, the skin. Thus, it can be pulled off easily without any damage to the skin. Frequently in the past, carbon-carbon backbones were utilized instead of silicone polymers, which caused a more rigid structure and, as a result, harm to skin. Silicone polymers, however, have methyl groups which interact only slightly with one another, producing little surface tension energy.  Additionally, silicone has a low adhesion in terms of sticking to the skin. When materials have diffusive adhesion, the molecules of each are soluble in the other material. They move around, and when joined, connect through diffusion. In particular, polymer chains demonstrate diffusive adhesion effectively, in which the ends of one molecule diffuses with another. 

Over 1.5 million injuries occur in the United States due to medical tape removal. Using this medical tape, this number can be reduced greatly, affecting numerous patients positively. 

http://articles.timesofindia.indiatimes.com/2012-10-30/health/34816599_1_tape-skin-release-liner