Medical tapes that affix breathing tubes and other life-saving devices to the skin are not only sticky, they are strong. After all, they must be wear resistant and must also resist shear forces between skin and tape that might dislodge the attached vital equipment. For babies and elderly patients, however, the tape itself poses a danger. When it is peeled off, it can tear sensitive skin and lead to discomfort and sometimes permanent scarring or worse. In the US, medical tape removal is responsible for 1.5 million injuries annually. To address the problem, a team led by Jeffrey Karp (Brigham and Women's Hospital and MIT) designed a tape that can take advantage of today's effective, nonirritating adhesives and durable backings, but that can be removed without injuring skin. Their innovation was to coat the backing with a nonadhesive layer and then use a laser to etch out microscopic regions of that intermediate material so that adhesive and backing layers could come in contact. That technique enabled the researchers to create a tape that distributes shear forces over a large area but that localizes stress when peel forces are applied. The result, as illustrated in the figure (and this movie), is that the tape easily pulls off above the adhesive and leaves a tacky layer that can be easily removed with gentle rubbing. (B. Laulicht, R. Langer, J. M. Karp, Proc. Natl. Acad. Sci. USA 109, 18803, 2012.)—Steven K. Blau
