Sequential Synthesis of Nanomaterials via Level-expansion

Nanotechnology is forging era-defining breakthroughs across science and engineering. In particular, one-dimensional nanostructures such as nanowires, nanotubes and nanobelts are widely regarded as critical building blocks for creating the next generation of devices in electronics, optics, energy and biomedicine. Motivated by a practical problem of sequential synthesis of nanowires, we propose a new statistical design augmentation method, called level-expansion. For a fractional factorial design at two levels, this method creates a follow-up design by expanding some of the factors in the initial design to four elaborately chosen levels and reversing the signs of the remaining factors.