Have you ever watched a beetle walk across the ceiling, appearing to defy the laws of gravity? What you're seeing is "wet adhesion," widely used in nature by insects and the like, and researchers in Taiwan are employing their crafted version of the technique to make patches that release drugs into the skin.
The team of scientists from the National Chung Hsing University constructed a self-adhesive patch with a capillary structure that mimics the way beetles' feet stick to a surface. Like a beetle, the patch employs an array of microfibers that create surface tension via a series of liquid bridges between one another, a phenomenon that uses both van der Waals and capillary forces.
The researchers loaded the patch, replete with "micro-pillars," with a non-steroidal anti-inflammatory drug, demonstrating that the patch's kinetics and friction allowed for the controlled release of the drug over a period of several days, according to the abstract in the Journal of Materials Chemistry B. And not only did the micro-pillars help with the delivery of the drug, but they helped with the strength of the device's adhesion.
"We imagined that if the secretions from capillaries on beetle feet were replaced with liquid drugs, a self-adhesive, auto-drug delivery patch would be achieved," said researcher Chen-Chung Chang, as reported by Chemistry World. "The adhesion and drug delivery of the patch still need to be assessed on skin before thinking about commercializing it."