• gripper
• microassembly
• three fingers

For the last ten years a miniaturisation process has spread in many different technical fields. This trend moved from the pressure of the electronic industry that crated a series of new products. These products present a set of novel problems to be solved for their manufacturing, handling and assemblying. Microassembly is one of the topic under a deep study and the research to automate the assembly operations would reduce its costs allowing a wide diffusion of these microproducts.
This work focuses on the study and characterisation of 3 different mechanical grippers: a 2 fingers gripper, and two 3 fingers one, the first is a planar one while the second works in an out-of-plane condition. This last gripper is the more complex and requested for an analytical and FEM study of its capability of performing a forced peg-in-hole operation. The work continued by designing the supports and interfaces for all the grippers and in several tests to evaluate the hysteresis of the devices.
All the grippers have been controlled via stepper motors, whose control has been developed within this thesis. Concerning the planar grippers the force is transmitted by using bowdens/wires, while the out-of-plane gripper is actuated by driving belt and two pulleys and srew-die coupling.
In conclusion, the planar 2 and 3 finger grippers demonstrated a good compliance, particularly interested for peg-in-hole with clearance, while the out-of-plane gripper was able to supply a high force, particularly important in forced peg-in-hole operations.