In this paper, we propose an original design for a manipulation system of rigid micro-objects by adhesion (50 /spl mu/m/spl sim/200 /spl mu/m) in open air. The design is based on a precise analysis of the mechanical conditions for manipulation by adhesion. Simulations using a dynamic model of a canonical manipulation (capture and release of micro-objects) have shown that it exists an "end-effector initial acceleration" windows for which manipulations are possible. The end-effector we have developed integrates a highly sensitive contact sensor and two piezo-accelerators (/spl sim/10/sup 6/ m.s/sup -2/). Successful manipulations by adhesion of silicon chips with a gold coated piezoresistive silicon cantilever have been carried out and are presented as conclusion of this paper.

Making a quadrupedal robotic machine walk is a problem with an infinity of solutions. Nevertheless, this question seems to have been solved successfully by mammals. Hence a particular approach in the design of walking robots has been considered, based on the animals movement characteristics. Indeed, studying animal walking can help produce a class of solutions towards the definition of quadrupedal robots. From this starting point, a model can be created according to a reduced number of criteria, notably the shape of the trajectory followed by the ankle or wrist during motion relatively to the hip or to the shoulder respectively. The problem lies in the difficulty to extract significant and valuable information from the mere observation of animals walking. This paper presents an experiment designed to extract angular variations data from the observation of a walking hedgehog and the use of these data to create a 2D dynamical simulation model to be used as an analysis basis.

Recent advances in robotics research show that applications of robot manipulators to complex assembly problems require the use of an intelligent terminal to generate compliant micro-motions. A new approach for complex assembly tasks consisting in the use of a manipulator-gripper, like a left hand, is presented here. Previous works have been concerned with the analysis and development of the manipulator-gripper to grip and manipulate objects of various shapes, and control grasp and contact forces. Experiments are being carried out to correct small variations in the relative position and orientation of assembly parts require further development towards high-level programming system.