In Touch with Atoms

Quantum mechanics has dramatically changed our perception of atoms, molecules, and condensed matter and established the central role of electronic states for electronic, chemical, and mechanical properties. Electronics, understood broadly as the motion of electrons and the deformation of their arrangements, has become the basis of our high-tech world, including “electronics,” computer science, and communications. Mechanics, on the other hand, understood as the motion of the mass of atomic cores and the deformation of their arrangements, played a lesser role, at best that of the guardian of the electron. Quantum mechanics has become, for many, synonymous with electronic states and electronics, whereas mechanics is considered the Stone Age. In this respect, the “mechanical” scanning tunneling microscope (STM) came as a surprise. The STM is a mechanically positioned, electrically sensitive kind of nanofinger for sensing, addressing, and handling individually selected atoms, molecules, and other tiny objects and for modifying condensed matter on an atomic scale (Sarid, 1991; Giintherodt and Wiesendanger, 1992; Chen, 1993; Stroscio and Kaiser, 1993; Hamers, Weaver, Weimer, and Weiss, 1996). And like with finger tips, it is the “touch” that makes the difference (see Fig. 1). Back to the future of mechanics: Nanomechanics, a new era.