Model Development and Control Design of Broadband Nanopositioners

In the past decade, it has become evident that nanotechnology will make fundamental contributions to science and technology in diverse areas including cell-biology, quantum computers and molecular machines. There are considerable challenges that need to be overcome before the promise of nanotechnology becomes a reality, pivotal among which is broadband nanopositioning. To overcome the challenge of providing angstrom resolution at ultra-high bandwidth, a concerted paradigm of modeling, control design, experimental validation and device fabrication is proposed in this investigation.

Ferroelectric materials are identified as the primary means to provide actuation for nanopositioning. However, they exhibit undesirable nonlinear behavior. In this investigation, these mechanisms will be quantified in a manner that promotes both a fundamental understanding of the underlying physics and will provide models amenable to control design and real-time implementation. The high-bandwidth nanopositioning demands are posed in a highly uncertain environment, and are multi-input multi-output in nature. In this investigation multiobjective robust control theory will be employed and enhanced with regard to nanopositioning. The theory addressed will be complemented by a comprehensive experimental setup that can be utilized to validate and suggest various strategies for nanopositioning.

This investigation will provide fundamental and broad contributions to atomic force microscopy. Based on the models and control theory developed in this initiative, in collaboration with Asylum Research, a new state of the art scanning probe microscope capable of achieving the speed and resolution required for future applications will be developed. To expose a broad range of students to this nascent field, related projects will be solicited for each of the 2002-2005 Industrial Mathematics Modeling Workshops sponsored annually by the Center for Research in Scientific Computation at North Carolina State University. In this manner, the investigation will strongly impact students as well as provide a mechanism for transferring the technology to a leading biology-related microscope manufacturer.