Vibrations and Nonlinear Dynamics of Microcantilevers Interacting with Nanoscale Structures: Applications to Atomic Force Microscopy

Purdue University, West Lafayette IN

Investigators

Abstract

Modeling and Development of Gradient Based Smart Polymer Sensors and Actuators Gregory Washington, PI Ohio State University Proposal # 0102310 Abstract The goal of this study is to develop a novel gradient-based sensor for spatial measurement of distributed systems. The sensors and actuators in this study are developed from polyvinylidene fluoride (PVDF). Previous studies have used spatial aperture shading techniques (spatially varying electrodes to achieve a particular performance function) to measure a myriad of distributed systems. A major limitation of the spatial aperture shading techniques was that the apertures have a heavy dependence on 1-dimensional variation for most cases. In this study spatial gradient polarization and aperture shading techniques are used to develop the next generation of sensors. In spatial polarization the material is polarized in a manner such that its piezoelectric constant is allowed to vary in controlled manner. Specifically, the objectives of this research are to: (1) Develop the analytical basis for spatial gradient polarization. Inherent in this part of the study is the development of techniques for analytically calculating weighting functions for various structural configurations. (2) Develop the experimental hardware and facilities necessary for making spatially polarized sensors and actuators. (3) Develop control techniques necessary for the production of user defined film actuators and sensors. (4) Develop a non-contact measurement technique for deflection verification. The research goals are accomplished by applying differential calculus, the principles of mechanics, and piezoelectric polymer modeling to a given sensor system. The experimental hardware that will be developed for polarizing the films consist of a corona charging system with an appropriate stretch and drive mechanism for correct placement and rastering of the film. A wide-angle stereo-photogrammetry system similar to those used in particle tracking applications will be modified to accurately measure the location of the distributed system when actuated. The sensors market is an $18 billion market and growing. These new sensors can be utilized in a host of applications including Automotive, Biomedical sensors, Aerospace Structural, and Impact sensors in Military applications, like sonar sensing equipment and so on. In addition, there is a possibility that this novel technology can be applied directly to piezoceramic actuators as well.