Abstract:
Linear theory of viscoelasticity has many parallels with LTI control systems, and identification methods for LTI can be applied to study viscoelastic materials. However, ...Show MoreMetadata
Abstract:
Linear theory of viscoelasticity has many parallels with LTI control systems, and identification methods for LTI can be applied to study viscoelastic materials. However, conducting such a study with atomic force microscopy (AFM) requires overcoming many challenges, including: (a) accurate piezo control of the tip trajectory; (b) calibration of the probe (spring constant and tip shape) and opto-mechanical system (inverse optical sensitivity); (c) converting z-position to indentation depth and limit error propagation of the conversion; (d) identification of the point of contact. Accounting for the tip shape also makes the viscoelastic models nonlinear. We describe the development of an AFM experiment and analysis that overcomes these challenges and demonstrate practical viscoelastic measurements at the nanometer scale.
Published in: 2018 Annual American Control Conference (ACC)
Date of Conference: 27-29 June 2018
Date Added to IEEE Xplore: 16 August 2018
ISBN Information:
Electronic ISSN: 2378-5861