From Nanotechnology to Nanoengineering

In those early days, nanotechnology referred to the possibility of synthesis via direct manipulation of atoms and molecules for fabrication of macroscale products. In the 1990, K. Eric Drexler and M. Minsky used the word “nanotechnology” in their book “Engines of Creation: The Coming Era of Nanotechnology” (Drexler and Minsky 1990), in which they proposed assembling machines and devices on the scale of molecules, a few nanometers wide. Later on, as nanotechnology became an accepted concept, the meaning of the word shifted to encompass technologies related to making any type of materials, structures and devices in nanometer scale. A nanometer (nm) is one-billionth of a meter, hundred-thousandth the width of a human hair. There is a multidisciplinary convergence of science dedicated to the study of a world in such small scale. The US National Nanotechnology Initiative (Roco 2011) has described four generations of nanotechnology development (Fig. 2.1). The first era is a design of passive nanostructures and materials to perform just one task like nanostructured metals, aerosol. The second phase introduced active nanostructures for multitasking, for example, actuators, drug delivery devices and sensors. The third generation featured nanosystems with thousands of interacting components. In this era, integrated nanosystems, hierarchical systems within systems, have been developed. Accordingly, a comprehensive definition for Nanotechnology is: