Multiphysics & Parallel Kinematics Modeling of a 3DOF MEMS Mirror

This paper presents a modeling for a 3DoF electrothermal actuated micro-electro-mechanical (MEMS) mirror used to achieve scanning for optical coherence tomography (OCT) imaging. The device is integrated into an OCT endoscopic probe, it is desired that the optical scanner have small footprint for minimum invasiveness, large and flat optical aperture for large scanning range, low driving voltage and low power consumption for safety reason. With a footprint of 2mm×2mm, the MEMS scanner which is also called as Tip-Tilt-Piston micro-mirror, can perform two rotations around x and y-axis and a vertical translation along z-axis. This work develops a complete model and experimental characterization. The modeling is divided into two parts: multiphysics characterization of the actuators and parallel kinematics studies of the overall system. With proper experimental procedures, we are able to validate the model via Visual Servoing Platform (ViSP). The results give a detailed overview on the performance of the mirror platform while varying the applied voltage at a stable working frequency. The paper also presents a discussion on the MEMS control system based on several scanning trajectories

Sliding Mode Impedance Controlled Smart Fingered Microgripper for Automated Grasp and Release Tasks at the Microscale

Part 5: Gripping and Handling Solutions in AssemblyInternational audienceThe grasp and release of objects have been widely studied in robotics. At the microscale, this problem becomes more difficult due to the microscale specificities which are notably manifested by the high dynamics of microsystems, their small inertia, their fragility, the predominance of surface forces and the high complexity of integrating adapted sensors.In this paper, the problem of the grasp/release task is considered at the microscale. A new nonlinear controller design based on Sliding Mode Impedance Control (SMIC) is proposed to automate the grasp/release of the micropart. The proposed controller controls dexterously the dynamic interaction between the microgripper and the micropart and forces the system to follow the desired dynamic relation (impedance). To perform the grasp/release task, a new smart-fingered-microgripper is designed. The microgripper is composed of an active finger with integrated force sensor and a passive finger.The grasp/release of a micropart of size 50 µm $$\times$$ 350 µm $$\times$$ 2 mm is tested in experiments using the control scheme and the developed microgripper. The microgripper design and the control scheme tested show their effectiveness for the grasp/release at the microscale