A tree grows strong from years of generating its own food. Now imagine if products could be strengthened with the same living materials that provide nutrients to strengthen trees. This is the work of USC Viterbi School of Engineering Civil and Environmental Engineering Professor Qiming Wang whose research lab is one of the first to infuse 3-D printer ink with living material. The material has potential for greater strength, to be flexible and self-heal. The work is documented in a paper published in The Proceedings of the National Academy of Sciences.
The idea for this bio-inspired ink came from trees that harness the power of photosynthesis to produce glucose that transform to cellulose and strengthen the plant's cell structure. "When trees are young," says Wang, "they are flexible, when they are mature, they are rigid. The research idea is also inspired by Popeye the Sailor, the animated character who can strengthen his muscles by eating spinach," says Wang, whose research is focused on bioinspired manufacturing and mechanics of unprecedented materials and structures that can potentially address engineering challenges in infrastructure, energy, robotics, healthcare and the environment. "Now, we are using scientific innovation to realize our childhood imagination," says Wang.
Some plants exhibit a self-healing capability during grafting and wound repairing. According to the researchers, the "living material" infused with chloroplasts in a lab at USC also presents an outstanding self-repairing property. Such a property is induced by the photosynthesis-produced glucose that creates the molecular process of cross-linking (in essence equivalent to creating sutures). Such crack-repairing capability could be applied in boat propellers or even drones.