No gentle tug at the corner for Sarah Bowen Shea. When she was kid, her sister would point to the sky, then reach over and yank the bandage off her knee in one excruciating swipe.
"She took such a perverse glee in it," Bowen Shea recalled.
Thanks to a new quick-release medical tape, this sort of sibling torture may soon be a thing of the past. Developed by biomedical engineers from MIT and Brigham and Women's Hospital in Boston, the new bandage covers wounds but lifts off without tugging the skin or ripping out body hair.
A conventional bandage sticks in place, thanks to a strong adhesive. Taking it off requires breaking the grip between the adhesive and the skin – and that's what causes the pain so many of us anticipate with mild dread. The new bandage has a three-layer design that allows the adhesive to stick to the tape itself rather than the skin, so removal is ouch-free.
Jeffrey Karp, one of the bandage's inventors and co-director of the center for regenerative therapeutics at Brigham Women's hospital, said the approach was inspired by a natural phenomenon known as anisotropy in which something is tough and durable depending on the direction of force. Think of wood, which is strong when force is applied along the grain but weaker when force is applied against the grain.
"The new tape is secure when you pull it or stretch it lengthwise, but when it's time to come off, it can be peeled away in a gentle upward motion," Karp said.
If any adhesive gunk remains on the skin, Karp said it can be rolled off with a finger with no discomfort.
Although a lot of "big babies" love the idea of a pain-free bandage, Karp said it was actually invented to protect the fragile skin of babies.
Most adhesive was developed for use on adults. Hospitals also use it to tape tubes, leads and monitors on premature infants, and when they remove it, it can cause severe damage to their skin. The adhesive bond is so strong, Karp said, it can rip off a baby's ear.
The research team evaluated problems in neonatal units all across the country and found that preventing medical-tape injuries to preemies topped the list. The researchers received funding to develop more skin-friendly bandage material from the nonprofit Children's Medical Ventures, which was set up by the health care company Phillips, and took about a year and a half to complete the project.
"We used readily available, cost-effective and low-toxic materials in hopes that we could clear regulatory barriers quickly and get the bandages into the hands of doctors and nurses who work with preemies and other patients with weak skin as soon as possible," Karp said.
Writing in this week's issue of the journal Proceedings of the National Academy of Sciences, the researchers speculated that clinical trials testing the bandages would start in the next few months but that the new bandages wouldn't make it onto drugstore shelves for at least a year.
In the meantime, Karp's own kids will continue to walk around for a little while longer with old, ragged bandages they refuse to strip off.