High precision robots for automated handling of micro objects

Abstract

Nanotechnology is a key issue in today’s and tomorrow’s development of advanced products. Soon new tools will be needed to automatically handle and assemble micro-sized objects with nanometer precision, or simply to give human beings the capability of operating in those tiny dimensions. Seeing emerging applications in this field, the Swiss Federal Institute of Technology at Zurich (ETHZ) decided to focus an interdisciplinary project on the theme “Nanorobotics”, ie automated handling of microparts with nanometer resolution. In this paper, after a short description of the goals and the approach taken in this project, some important aspects of the design of high precision robots are stressed. It is especially shown that if a minimum of 6 independent degrees-of-freedom (dof) is required to freely position an object in space, redundant robots will lead to less complicated and more efficient mechanical structures. It is then shown, that if a global sensor is used, measuring the relation gripper-object, the only requirement for the mechanical structure is a good resolution. Finally, two new 3 dof planar robot designs are presented. Both of them have unlimited range of motion while having a resolution down to 10 nm. One of them has been controlled using a vision feedback under a light microscope and showed very promising results