Researchers at Northwestern University have created a dime-sized robot that looks like an animal you might find at the bottom of the sea. The soft robot is almost 90 percent water by weight. It has a hydrogel exterior while its nickel skeleton allows it to change shape. It doesn't use hydraulics or electricity to move around. Instead, the researchers used a chemical synthesis process to program molecules to respond to light. When the robot is exposed to light, the molecules can repel water.
A glue that works underwater and can stick objects together in mere seconds has been developed by a team of researchers from Japan. The aquatic adhesive sticks to materials including glass, metals and rocks -- and works by harnessing the electric force between molecules to stick to surfaces. This so-called'electrostatic attraction' works in a similar way to how a party balloon can be stuck to the ceiling by rubbing its surface to create an electric charge. This method of sticking things together lasts longer than previous'waterproof' glues, which imitated the natural adhesives found in marine animals like barnacles. Unfortunately, such naturally-inspired glues have been found to quickly oxidise, causing them to lose their adhesiveness.
A new material is the stuff of envy for muscleheads everywhere: it bulks up and self-strengthens without ever needing to hit the gym. Takahiro Matsuda and his colleagues at Hokkaido University in Japan have developed a "self-growing" hydrogel, which improves its size and strength after repeated mechanical force. They believe it could be used to make flexible exosuits, for people with skeletal injuries, which become stronger the more they are used. Hydrogels are soft, flexible materials that come in a wide variety of forms: they're …
Hydrogels are composed of cross-linked polymers that are highly swollen with water. They are typically soft, squishy, and elastic, but they are not known for their strength or toughness. Gonzalez et al. show that unstructured proteins, namely, those that do not have folds or coils, can form the basis for strong, tough, and self-adhesive hydrogels. They genetically engineered Escherichia coli to produce elastic-like polypeptides with domains that are able to either covalently cross-link or form metal bonds with Zn2 ions. The covalent cross-links provide the strength, and the reversible metal cross-links allow for the dissipation of energy and toughness when the hydrogel is stretched.
A soft gel made of 80 per cent water has similar properties to shatterproof glass and can withstand being run over by a car 16 times without lasting deformation. The material could be useful for a range of applications including soft robots, prosthetics and wearable devices. Hydrated polymer networks, or hydrogels, that have been made before are soft and stretchable, with rubber-like properties. But under high compression, these gels fail to bounce back to their original shape. Now Oren Scherman and his colleagues at the University of Cambridge have created a soft and compression-resistant gel that can rapidly return to its original shape within a couple of minutes, even after being repeatedly squished by a car weighing 1200 kilograms.