Like most people, you have probably lost count of the number of perfectly pristine-looking shoes you have tossed out simply because the rubber soles are cracked. In addition to the expense and hassle of replacing footwear, it is also harmful to our environment. According to the U.S. Department of the Interior, 300 million pairs of shoes end up in landfills each year, where they can take 30 to 40 years to decompose. Now, thanks to a revolutionary self-healing 3-D printed rubber material, fractured shoe soles may be a thing of the past.
The magical polymer is the brainchild of researchers at the University of Southern California's (USC) Viterbi School of Engineering and the University of Connecticut (UConn). The team, led by USC Assistant Professor Qiming Wang and UConn Assistant Professor Ying Li, created it through a process called photopolymerization, which uses light to solidify the liquid resin used to create 3-D printed plastic. The researchers found that adding the right proportion of oxidizer to the liquid resin allowed the 3-D polymer to heal without slowing down the hardening process.