Direct user interaction in microrobotics is a challenge because of the scale of treated objects, the complexity of the physical phenomena and the high impact of environmental conditions. Teleoperation in this case is a promising approach to supplement human perception. Its success requires a control scheme guaranteeing transparency and stability, to represent complex physical phenomena to the user without degradation. Although several control schemes are proposed with good performances, it clearly appears that there is room for improvement especially in regard to specificities of multiscale haptic coupling, the rendering of the haptic information, force sensing at the microscale, the mechanics of measurement devices... Several issues need to be addressed in this purpose : design of an adapted haptic device, design of a force sensor with proper dynamic properties and bandwidth, development of a case-specific control scheme and implementation of bilateral coupling between the haptic device and the force sensor. Therefore, this thesis describes a novel teleoperation chain for microscale force probing. Experimental validations are carried out, with single axis measurements on a water droplet. The system is also tested by several user with no experience in microscale phenomena. All the test subjects were able to correctly master the approach-and-retreat operations. Various interaction forces, pull-in and pull-off phenomena are correctly rendered. The proposed system is a proof-of-concept of a new design for a microscale force sensing tool, a high-fidelity haptic device, and appropriate bilateral coupling.
Design of a stable and transparent micro teleoperation system