Inspired by mussels’ ability to adhere to many surfaces underwater, German researchers have developed a group of adhesives that are waterproof, can bind themselves together, react with surfaces, degrade with light, and are biocompatible.
The materials have applications in medicine, reports Azom.com. They could be used for removable hydrogel pads that help regenerate skin or as a reversible superglue for repeated operations. The researchers wrote about their development in the journal, Angewandte Chemie.
Adhesives today have incredible bonding strength. They can hold together airfoils on airplanes, for example. However, there is a need for other applications as well: bonding that can occur underwater, repairs for underwater pipelines, sealing of bleeding wounds during operations, “self-healing” adhesives that would prevent catastrophic failures, and “on demand” debonding without residues to allow for replacement of components.
Mussels use the amino acid, dihydroxyphenylalanine (DOPA), to stick to all types of surfaces. The acid mixes with seawater to forum a polymer matrix capable of bonding to inorganic oxides in rock. Also, they bind to polyvalent metal ions, such as iron ions, that give the mussel adhesive the ability to self-heal.
Researchers at the Max Planck Institute for Polymer Research in Mainz produced polymers with DOPA-like components that self-healed; it takes a few minutes for a sliced gel sample to grow back together. Also, the adhesive can be split by irradiation with ultraviolet light. This characteristic means that the adhesive can be debonded.
Source: “Mussels Inspire Biocompatible Adhesive with Amazing Properties,” Azom.com, 4/15/12
Image by JoJan, used under its Creative Commons license.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.