Nano-wires have fascinated and intrigued researchers for decades. These extremely thin and elongated structures (10−9 meter) are considered to be promising materials for high efficiency electronic devices. They are particularly useful in chemical and biological sensors, solar cells, field emission devices, and lasers. But crucial parts of the process that guide their growth remained a mystery. Now Professor Albert Nasibulin, a researcher at Skoltech, teamed up with colleagues from Denmark and Finland to reveal new facts about the behavior of nano-wires during metal oxidation: the process occurs without catalysts and is guided by planar defects. Simply put, faults serve as both guides and engines for growth. The researchers published their findings in the scientific journal Nano Letters. These could help future efforts to control the properties of nano-wires.