Project Details
Accessing the contact mechanics of particle systems with an emphasis on the interaction with specific technological relevant surfaces based on scanning probe techniques
Applicant
Dr. Thorsten Staedler
Subject Area
Mechanical Process Engineering
Term
from 2010 to 2018
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 169416013
Basic motivation of the project proposed here is to develop and provide experimental techniques, which allow for the access of key parameters of the mechanical contact between particles and particles and generic surfaces. As we aim for particles featuring radii ranging from a few tenth of nanometers up to 100 µm, it is crucial to establish a nanoindentation based technique in addition to the standard atomic force microscopy (AFM) based colloid probe technique. The nanoindentation based technique that we suggest is set up in analogy to the AFM one. Aside from the option of handling larger particles, the principles of nanoindentation offer test options, which are almost impossible to realize with a cantilever based system, i.e. AFM. Such examples include the measurement of rolling friction as well as torsional phenomena of spherical particles via a flat punch approach.The key parameters mentioned above are identified by means of a continuous scientific exchange with the groups of the key research program dedicated to the appropriate contact models. As we were already able to show the general validity of our strategies within the first project phase, the second phase was used to improve these methods and adapt them to actual modelling tasks. During these collaborations distinct goals with respect to the experimental work were recognized. In principle, two key tasks were identify, which will guide our activities in the final phase. The first task is to rigorously continue the pursuit of the decoupling of force and displacement by means of an external piezo-positioning setup. The second task is to track and characterize any contact based permanent changes to the topography of the contacting partners. Subsequently, any changes in topography will have to be correlated with potential changes in the contact behavior.
DFG Programme
Priority Programmes