Has this ever happened to you? While glass and plastic can shatter and crack, researchers have been hard at work developing materials that can be easily reassembled, using strings of molecules called polymers. Healable polymers are not a new idea, but previous versions were either soft, making making them impractical for most applications, or they required high temperatures to merge the pieces back together. Using a pair of molecules linked together, researchers have developed a new kind of semi-transparent material, that maintains both rigidity and healing properties, without requiring any external heating. The key to this process lies in the design of dense hydrogen bonds that keep the polymer together. The hydrogen bonds form in a such a way that the polymer doesn’t crystallize, giving the chains the ability to move freely, and combine when compressed. Different kinds of linkers were tested, such as TUEG2 and TUC8, but the best-behaved was TUEG3. After being cut and gently compressed for 30 seconds, a 2 square centimeter sheet can hold 300 grams of weight, roughly the same as a full can of soda. And the longer it’s compressed, the stronger the bonds become. In the future, this rigid polymer could be used to make robots and other technology that can be easily repaired, and maybe even let you fix a broken window.