In the X-Men comic books, Wolverine's mutant power is an accelerated healing process, allowing him to regenerate damaged tissues within seconds. Now, a new material could see Wolverine's self-healing talents replicated in real-life. Researchers have developed a new self-healing substance that regenerates itself opening up the possibility of creating robots that repair themselves. Previously, another author of the study, Christoph Keplinger, had produced a material that was stretchable, transparent, and an ionic conductor, but it lacked the ability to self-heal. The key difficulty was finding bonds that were stable and reversible under electrochemical conditions.
Imagine a material that, when cut, can repair itself -- à la Wolverine from "X-Men" -- and is transparent, extremely stretchable, as well as highly conductive. Scientists believe that such a material, if developed, can be used -- among other things -- to create "self-healing" robots and to increase the life of lithium-ion batteries. A team of researchers described, in a study published Friday in the journal Advanced Materials, the creation of such an ionic conductor -- one that is transparent, stretchable and self-healing. The rubber-like material can stretch to a staggering 50 times its original length, and can "heal" in a span of just 24 hours after being cut at room temperature. Moreover, just five minutes after healing, it can be stretched to two times its original length.
Self-assembly by intermolecular noncovalent interactions directed by self-recognition created the field of supramolecular chemistry (1). However, the word "self" appears to limit this field to mixing components in one assembly step where most of the complexity is inherent in the covalently synthesized reactants, rather than the result of a series of assembly steps that build more complex structures in reproducible procedures. The paradigm shift in supramolecular chemistry that we propose is the building of multicomponent systems following a multistep pathway--the emergence of molecular complexity (see the figure). The latter is not only directed by the information stored in the covalent framework of the components, but also controlled by the kinetics and thermodynamics of the reaction pathways selected in processing this information (2). Although noncovalent synthesis was quoted by Whitesides and Reinhoudt in the 1990s (3, 4), it has never been broadly accepted nor used.
Poke a hole in a human and something remarkable happens. First of all, you go to jail. Poke a hole in a robot, however, and prepare for a long night of repairs. The machines may be stronger than us, but they're missing out on a vital superpower. Researchers at Belgium's Vrije Universiteit Brussel report this week in Science Robotics that they've developed a squishy, self-healing robot.
Even though halogen atoms are highly electronegative, a noncovalent bond can form between an electron donor and a halogen atom in a covalent bond. Such interactions are facilitated by the formation of electron-depleted regions in the halogen's covalent bond, a situation least likely for fluorine atoms. Han et al. used noncontact scanning tunneling microscopy with submolecular resolution to explore how the size and polarizability of halogens affect complex formation by halogenated benzene molecules adsorbed on a silver surface (see the Perspective by Neaton). Science, this issue p. 206; see also p. 167