A high-precision planar digital electromagnetic actuator with two displacement directions and four discrete positions is presented in this paper. The four discrete positions are located at each corner of a square cavity where a mobile permanent magnet moves thanks to Lorentz forces generated when a driving current passes through two orthogonal wires placed below the cavity. Four fixed permanent magnets are placed around the cavity in order to ensure high-precision magnetic holding of the mobile magnet at each discrete position. An analytical model of the actuator is presented and used to characterize its properties (switching time, energy consumption, and displaceable mass). Based on this model, an experimental prototype has been developed and then characterized. Comparisons between experimental and simulated results are carried out and show good agreement. The positioning repeatability errors have also been characterized according to the input signal in order to qualify the digital behavior of this high-precision actuator. Finally, an application of this digital actuator as a linear conveyor is presented and experimentally tested.

In this paper, a remote optical method to localize and track a mobile micro-conveyor is presented. The principle of the proposed method consists of detecting a laser beam that is reflected by the micro-conveyor and analyzing this optically received signal to obtain the corresponding positions of the micro-conveyor. The main elements of the system are a corner cube retroreflector, a steering mirror, and a beam splitter. The corner cube retroreflector is placed onto the micro-conveyor in order to allow the optical signal to be reflected back in its incident direction. The steering mirror aids in scanning the surface with the laser. The beam splitter is used to guide the reflected laser beam towards a quadrant photodiode, which interprets the optical signal to corresponding output voltages. In this work, a micro-conveyor is successfully localized and tracked with a resolution better than 55 μm, over a surface of 100 mm×100 mm, with a displacement velocity of 30mm/s.

Micro-electro-mechanical systems (MEMS) mirrors are key components in precision optical systems, enabling miniature, low-inertia scanning and accurate beam steering solutions. They offer high operating frequencies in the kHz range and angular resolutions below the millidegree. While many studies have addressed the improvement of MEMS tempral and angular response, calibration, and integration into larger systems such as LiDAR, there is still a lack of detailed calibration methods that accurately describe MEMS behavior in their operating environment. This paper addresses this gap through a comprehensive and structured calibration methodology. The proposed approaches based on a video calibration in which we analyse the positioning of the camera and the selection of the calibration plane. These two parameters have a significant influence on the accuracy and repeatability of the system. Analytical calculations are provided to determine the three-dimensional position and orientation of the MEMS mirror within a reference frame. The repeatability of the camera-based measurement system is evaluated. A comparative study is also conducted between two methods for estimating the laser line direction, using either two or five points per line. The results show that using five points improves the accuracy of the MEMS mirror pose estimation. The second part of the method focuses on evaluating the electrical response curve of the MEMS device. The effect of the perpendicularity between the mirror and the calibration plane is examined, and the principle of the method is explained in detail. A surface fitting approach is introduced to model the response behavior of the MEMS mirror more accurately across its entire operational range, resulting in a more precise and reliable characterization. This complete calibration process provides robust and accurate system characteristics that are essential for high-precision optical applications.