Hydrogel superglue is 90 percent water
Nature has developed innovative ways to solve a sticky challenge: Mussels and barnacles stubbornly glue themselves to cliff faces, ship hulls, and even the skin of whales. Likewise, tendons and cartilage stick to bone with incredible robustness, giving animals flexibility and agility. The natural adhesive in all these cases is hydrogel — a sticky mix of water and gummy material that creates a tough and durable bond. Now engineers at MIT have developed a method to make synthetic, sticky hydrogel that is more than 90 percent water. The hydrogel, which is a transparent, rubber-like material, can adhere to surfaces such as glass, silicon, ceramics, aluminum, and titanium with a toughness comparable to the bond between tendon and cartilage on bone. In experiments to demonstrate its robustness, the researchers applied a small square of their hydrogel between two plates of glass, from which they then suspended a 55-pound weight. They also glued the hydrogel...