Researchers, Xi Chen and Tetsushi Taguchi tweaked a widely used polymer, poly (vinyl alcohol) (PVA) to create a potential new adhesive to keep wearable sensors in place. The new adhesive is not irritating to the skin and is currently used in wound dressings, contact lenses and other similar items.
Bio-inspired Adhesives Impractical for Mass Production
Wearable sensors are often put in place using acrylic-based medical bandages. However, the adhesives on these bandages can provoke allergic reactions or cause pain when removed. Another option, silicone-based adhesives, doesn’t cause irritation, but also doesn’t stay put. Other adhesives, including bio-inspired ones that mimic gecko feet and octopus’ suckers, are not yet practical for mass production.
4C3-PVA - Promising Adhesive for Wearable Devices
Despite its many appealing properties, PVA can come off easily when wet. So, the researchers modified the compound by adding alkyl chains to try to improve its adhesion. They made versions with chains that contained three, six or nine methylene carbons, then tested them to see which performed best. It turned out that films made of longer chain versions were more hydrophobic but had less tensile strength. Cells best tolerated the short chain known as 4C3-PVA, and in tests with pig skin, they found it bonded most strongly. The researchers conclude that 4C3-PVA is a promising adhesive for wearable devices.
Source: ACS Omega