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In order to satisfy the demand for the high functionality of future microdevices, research on new concepts for multistable microactuators with enlarged working ranges becomes increasingly important. A challenge for the design of such actuators lies in overcoming the mechanical connections of the moved object, which limit its deflection angle or traveling distance. Although numerous approaches have already been proposed to solve this issue, only a few have considered multiple asymptotically stable resting positions. In order to fill this gap, we present a microactuator that allows large vertical displacements of a freely moving permanent magnet on a millimeter-scale. Multiple stable equilibria are generated at predefined positions by superimposing permanent magnetic fields, thus removing the need for constant energy input. In order to achieve fast object movements with low solenoid currents, we apply a combination of piezoelectric and electromagnetic actuation, which work as cooperative manipulators. Optimal trajectory planning and flatness-based control ensure time- and energy-efficient motion while being able to compensate for disturbances. We demonstrate the advantage of the proposed actuator in terms of its expandability and show the effectiveness of the controller with regard to the initial state uncertainty.
Michael Olbrich; Arwed Schütz; Tamara Bechtold; Christoph Ament. Design and Optimal Control of a Multistable, Cooperative Microactuator. Actuators 2021, 10, 183 .
AMA StyleMichael Olbrich, Arwed Schütz, Tamara Bechtold, Christoph Ament. Design and Optimal Control of a Multistable, Cooperative Microactuator. Actuators. 2021; 10 (8):183.
Chicago/Turabian StyleMichael Olbrich; Arwed Schütz; Tamara Bechtold; Christoph Ament. 2021. "Design and Optimal Control of a Multistable, Cooperative Microactuator." Actuators 10, no. 8: 183.
In this work, we perform a two-stage design optimization of the folded beam multi-resonant piezoelectric energy harvester. The optimization routine involves a global pre-optimization using evolutionary algorithm and a subsequent local optimization by classical non-linear programming. Optimization resulted in designs, which shows promising characteristics in simulation. For the validation of simulation results, we fabricated the optimal designs and performed experimental characterization. Simultaneously, we developed a comparable array of single beam piezoelectric harvesters, which we compared with the optimized folded beam designs. Both new designs significantly outperform the initial one in terms of frequency spacing. Furthermore, the experimental data demonstrate that the optimized folded beam designs generate considerably higher maximum voltage compared to the proposed array-structured designs.
Siyang Hu; Sofiane Bouhedma; Arwed Schütz; Simon Stindt; Dennis Hohlfeld; Tamara Bechtold. Design optimization of multi-resonant piezoelectric energy harvesters. Microelectronics Reliability 2021, 120, 114114 .
AMA StyleSiyang Hu, Sofiane Bouhedma, Arwed Schütz, Simon Stindt, Dennis Hohlfeld, Tamara Bechtold. Design optimization of multi-resonant piezoelectric energy harvesters. Microelectronics Reliability. 2021; 120 ():114114.
Chicago/Turabian StyleSiyang Hu; Sofiane Bouhedma; Arwed Schütz; Simon Stindt; Dennis Hohlfeld; Tamara Bechtold. 2021. "Design optimization of multi-resonant piezoelectric energy harvesters." Microelectronics Reliability 120, no. : 114114.
This work investigates a new type of microactuator for optical applications and a new type of assembly that incorporates free flight phases to overcome the lack of ball bearings in microsystems. Presented design employs electromagnets to manipulate the flying object, conceived as a freely moving micromirror without any limitation of the maximum deflection angle. A fast and precise system-level model enables the micromirror's vertical position-control, thus achieving the desired accuracy for optical applications. This paper evaluates the performance of three system-level models based on magnetostatic finite element simulations. These are a lookup table, a semi-analytical compact model and a parametric reduced order model constructed by matrix interpolation method. All system-level models compete in computational time and accuracy, achieving an excellent match to the reference solution. Finally, an application within a control loop demonstrates their feasibility.
Arwed Schütz; Michael Olbrich; Siyang Hu; Christoph Ament; Tamara Bechtold. Parametric system-level models for position-control of novel electromagnetic free flight microactuator. Microelectronics Reliability 2021, 119, 114062 .
AMA StyleArwed Schütz, Michael Olbrich, Siyang Hu, Christoph Ament, Tamara Bechtold. Parametric system-level models for position-control of novel electromagnetic free flight microactuator. Microelectronics Reliability. 2021; 119 ():114062.
Chicago/Turabian StyleArwed Schütz; Michael Olbrich; Siyang Hu; Christoph Ament; Tamara Bechtold. 2021. "Parametric system-level models for position-control of novel electromagnetic free flight microactuator." Microelectronics Reliability 119, no. : 114062.
A current goal for microactuators is to extend their usually small working ranges, which typically result from mechanical connections and restoring forces imposed by cantilevers. In order to overcome this, we present a bistable levitation setup to realise free vertical motion of a magnetic proof mass. By superimposing permanent magnetic fields, we imprint two equilibrium positions, namely on the ground plate and levitating at a predefined height. Energy-efficient switching between both resting positions is achieved by the cooperation of a piezoelectric stack actuator, initially accelerating the proof mass, and subsequent electromagnetic control. A trade-off between robust equilibrium positions and energy-efficient transitions is found by simultaneously optimising the controller and design parameters in a co-design. A flatness-based controller is then proposed for tracking the obtained trajectories. Simulation results demonstrate the effectiveness of the combined optimisation.
Michael Olbrich; Arwed Schütz; Koustav Kanjilal; Tamara Bechtold; Ulrike Wallrabe; Christoph Ament. Co-Design and Control of a Magnetic Microactuator for Freely Moving Platforms. Proceedings of 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications 2020, 64, 23 .
AMA StyleMichael Olbrich, Arwed Schütz, Koustav Kanjilal, Tamara Bechtold, Ulrike Wallrabe, Christoph Ament. Co-Design and Control of a Magnetic Microactuator for Freely Moving Platforms. Proceedings of 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications. 2020; 64 (1):23.
Chicago/Turabian StyleMichael Olbrich; Arwed Schütz; Koustav Kanjilal; Tamara Bechtold; Ulrike Wallrabe; Christoph Ament. 2020. "Co-Design and Control of a Magnetic Microactuator for Freely Moving Platforms." Proceedings of 1st International Electronic Conference on Actuator Technology: Materials, Devices and Applications 64, no. 1: 23.
In this paper, we present a macroscale multiresonant vibration-based energy harvester. The device features frequency tunability through magnetostatic actuation on the resonator. The magnetic tuning scheme uses external magnets on linear stages. The system-level model demonstrates autonomous adaptation of resonance frequency to the dominant ambient frequencies. The harvester is designed such that its two fundamental modes appear in the range of (50,100) Hz which is a typical frequency range for vibrations found in industrial applications. The dual-frequency characteristics of the proposed design together with the frequency agility result in an increased operative harvesting frequency range. In order to allow a time-efficient simulation of the model, a reduced order model has been derived from a finite element model. A tuning control algorithm based on maximum-voltage tracking has been implemented in the model. The device was characterized experimentally to deliver a power output of 500 µW at an excitation level of 0.5 g at the respected frequencies of 63.3 and 76.4 Hz. In a design optimization effort, an improved geometry has been derived. It yields more close resonance frequencies and optimized performance.
Sofiane Bouhedma; Yongchen Rao; Arwed Schütz; Chengdong Yuan; Siyang Hu; Fred Lange; Tamara Bechtold; Dennis Hohlfeld. System-Level Model and Simulation of a Frequency-Tunable Vibration Energy Harvester. Micromachines 2020, 11, 91 .
AMA StyleSofiane Bouhedma, Yongchen Rao, Arwed Schütz, Chengdong Yuan, Siyang Hu, Fred Lange, Tamara Bechtold, Dennis Hohlfeld. System-Level Model and Simulation of a Frequency-Tunable Vibration Energy Harvester. Micromachines. 2020; 11 (1):91.
Chicago/Turabian StyleSofiane Bouhedma; Yongchen Rao; Arwed Schütz; Chengdong Yuan; Siyang Hu; Fred Lange; Tamara Bechtold; Dennis Hohlfeld. 2020. "System-Level Model and Simulation of a Frequency-Tunable Vibration Energy Harvester." Micromachines 11, no. 1: 91.