Black and Blue all over: Scientists Discover a Method to Make Concrete Bruise Like a Bumped Knee.

Posted by Tim Martin 

Recently a research team from the Structural Composite Research Center at the Institute of Advanced Composite Materials, which is part of the Korean Institute of Science and Technology, has improved the mechano-sensitivity of spiropyran. spiropyran reacts to an external force that converts it into merocyanine, which appears blue in light. Before the recent development spiropyran was not sensitive enough for real life applications, for instance when injected into concrete or silicone the deformation of the parent material must be drastic for the spiropyran to visibly convert to merocyanine . However, a more sensitive polymer will not only allow for safer building materials but also the use of spiropyran in wearable sensors for artificial skin, a leap forward for the medical field. The research group enhanced spiropyran’s sensitivity to stimuli by first synthesizing a composite material and then applying a solvent mixture of spiropyran, which “ages” the molecule and makes it more fragile to force. The formed polymer showed up to a 850% improvement as compared to polymers produced through other,more traditional methods. The solvent approach also allows for the application of spiropyran by manipulating the solvent mixture based on the target material. The polymer is so sensitive it can now react to tension compression and bending, exceeding its prior applications in building materials.