Development of a new nanotribometer with multi asperity contact.

Abstract

International audienceIt is often difficult to make a connection between the tribological properties really assessed for a single asperity and the ones which involve the whole asperities in a microcontact. We propose a new apparatus development based on passive diamagnetic levitation (PDL) that can be used to study friction in microcontact with a lower range of force than with classical nanotribometers. This sensor measures micro and nanoforces. Its sensitive part is a ten centimeters long glass capillary tube used as a horizontal levitating seismic mass (20 to 80 mg). This rigid part is connected to a magnetic spring with stiffness between 0.01 and 0.03 N/m. The measurement range is 100μN with a resolution between one and five nanonewton. In order to validate this sensor in a multi asperity nanotribological context, this part is used to measure tangential friction forces generated by spherical micro-objects sliding on flat substrate. Results are compared with the ones provided by a classical multiasperity nanotribometer