Rotary Silicon Polymeric Composite Thermal Micro-Actuator

2013 ◽  
Author(s):  
Jiaping Yang ◽  
Cheng Peng Tan ◽  
Nyok Boon Chong ◽  
Gih Keong Lau
Keyword(s):  
Resonance Frequency ◽  
Lateral Displacement ◽  
Operation Mode ◽  
Polymeric Composite ◽  
Positioning Systems ◽  
Head Slider ◽  
Micro Actuator ◽  
Step Voltage ◽  
Wide Range ◽  
Dual Stage

This paper reports a new rotary thermal micro-actuator. This new thermal actuator uses a pair of powerful silicon-polymeric composite benders to actuate a magnetic head slider into a rotation when the expandable polymer elements are resistively heated. The advantage is the rotary micro-actuator design can move the read/write head slider with a larger lateral displacement by using a new T-shape central hinge joint as compared to the previous translational design. The experimental results demonstrate that the prototyped device can reach up 314nm displacement by a 4V step voltage. The 1st mechanical resonance frequency has been pushed up to 35 kHz. Simulation shows that the micro-actuator can be subjected to 1000G shock loading under non-operation mode. The large displacement, high resonance frequency and robust shock resistance make the rotary thermal micro-actuator be very suitable for a wide range of precise positioning systems applications including dual-stage positioning systems in disk drives and resonance switches in microsystems.

Nano-and Micro-Actuations of Hard Disk’s Head Positioning System: Precision Control and Evaluation

2006 ◽  
Author(s):  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Controller Design ◽  
Lateral Displacement ◽  
Hard Disk Drives ◽  
Pole Placement ◽  
Flying Height ◽  
Positioning System ◽  
Positioning Systems ◽  
Height Control ◽  
Micro Actuator ◽  
Head Positioning

A new piezoelectric micro-actuator with 2-dimensional control, i.e., a track following control and a flying height control, of the head positioning system for high-density hard disk drives (HDD) was previously developed in our lab. In this study, control algorithms for the new 2-degree-of freedom (DOF) micro-actuator are developed to independently control the lateral displacement and the transverse deflection to against various disturbances and system uncertainties. The structure of the piezoelectric micro-actuator is reviewed briefly. Then, the overall control strategy for the micro-actuator system is discussed. Next, controller design schemes for each DOF are presented. The pole placement method is used to design controllers. To obtain compensation for overshoot and settling time, pole and zero locations are carefully chosen. First, the control law is defined for the disturbance rejection. Second, the estimator is designed for noise reduction. Lastly, the reference input is added for the command following. Simulation results show that the proposed controllers in the closed-loop system provide good stability, and compensate for disturbances and noises. The data suggest that the proposed micro-actuator control system considerably improves track following and flying height control of head positioning systems in highdensity HDDs.

scholarly journals Focusing of Particles in a Microchannel with Laser Engraved Groove Arrays

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 263
Author(s):  
Tianlong Zhang ◽  
Yigang Shen ◽  
Ryota Kiya ◽  
Dian Anggraini ◽  
Tao Tang ◽  
...  
Keyword(s):  
Open Space ◽  
Lateral Displacement ◽  
Reynolds Numbers ◽  
Secondary Flows ◽  
Particle Sedimentation ◽  
Nanoparticle Separation ◽  
Wide Range ◽  
Fs Laser ◽  
Channel Bottom ◽  
Myoblast Cells

Continuous microfluidic focusing of particles, both synthetic and biological, is significant for a wide range of applications in industry, biology and biomedicine. In this study, we demonstrate the focusing of particles in a microchannel embedded with glass grooves engraved by femtosecond pulse (fs) laser. Results showed that the laser-engraved microstructures were capable of directing polystyrene particles and mouse myoblast cells (C2C12) towards the center of the microchannel at low Reynolds numbers (Re < 1). Numerical simulation revealed that localized side-to-center secondary flows induced by grooves at the channel bottom play an essential role in particle lateral displacement. Additionally, the focusing performance proved to be dependent on the angle of grooves and the middle open space between the grooves based on both experiments and simulation. Particle sedimentation rate was found to critically influence the focusing of particles of different sizes. Taking advantage of the size-dependent particle lateral displacement, selective focusing of micrometer particles was demonstrated. This study systematically investigated continuous particle focusing in a groove-embedded microchannel. We expect that this device will be used for further applications, such as cell sensing and nanoparticle separation in biological and biomedical areas.

scholarly journals Poly(Propylene Fumarate)–Hydroxyapatite Nanocomposite Can Be a Suitable Candidate for Cervical Cages

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Yong Teng ◽  
Hugo Giambini ◽  
Asghar Rezaei ◽  
Xifeng Liu ◽  
A. Lee Miller ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Moduli ◽  
Failure Load ◽  
Polymeric Composite ◽  
Materials Testing ◽  
Bulk Materials ◽  
Suitable Candidate ◽  
Salt Leaching ◽  
Wide Range ◽  
Poly Propylene

A wide range of materials have been used for the development of intervertebral cages. Poly(propylene fumarate) (PPF) has been shown to be an excellent biomaterial with characteristics similar to trabecular bone. Hydroxyapatite (HA) has been shown to enhance biocompatibility and mechanical properties of PPF. The purpose of this study was to characterize the effect of PPF augmented with HA (PPF:HA) and evaluate the feasibility of this material for the development of cervical cages. PPF was synthesized and combined with HA at PPF:HA wt:wt ratios of 100:0, 80:20, 70:30, and 60:40. Molds were fabricated for testing PPF:HA bulk materials in compression, bending, tension, and hardness according to ASTM standards, and also for cage preparation. The cages were fabricated with and without holes and with porosity created by salt leaching. The samples as well as the cages were mechanically tested using a materials testing frame. All elastic moduli as well as the hardness increased significantly by adding HA to PPF (p < 0.0001). The 20 wt % HA increased the moduli significantly compared to pure PPF (p < 0.0001). Compressive stiffness of all cages also increased with the addition of HA. HA increased the failure load of the porous cages significantly (p = 0.0018) compared with nonporous cages. PPF:HA wt:wt ratio of 80:20 proved to be significantly stiffer and stronger than pure PPF. The current results suggest that this polymeric composite can be a suitable candidate material for intervertebral body cages.

High-bandwidth controller design for dual-stage actuator system in hard disk drives

2022 ◽  
pp. 107754632110623
Author(s):  
Shota Yabui ◽  
Takenori Atsumi
Keyword(s):  
Controller Design ◽  
Hard Disk Drives ◽  
Voice Coil Motor ◽  
Hard Disk ◽  
Disk Drives ◽  
Positioning Accuracy ◽  
Micro Actuator ◽  
Dual Stage ◽  
Actuator System ◽  
Dual Stage Actuator

Large-capacity hard disk drives are important for the development of an information society. The capacities of hard disk drives depend on the positioning accuracy of magnetic heads, which read and write digital data, in disk-positioning control systems. Therefore, it is necessary to improve positioning accuracy to develop hard disk drives with large capacities. Hard disk drives employ dual-stage actuator systems to accurately control the magnetic heads. A dual-stage actuator system consists of a voice coil motor and micro-actuator. In micro-actuators, there is a trade-off between head-positioning accuracy and stroke limitation. In particular, in a conventional controller design, the micro-actuator is required to actuate such that it compensates for low-frequency vibration. To overcome this trade-off, this study proposes a high-bandwidth controller design for the micro-actuator in a dual-stage actuator system. The proposed method can reduce the required stroke of the micro-actuator by increasing the gain of the feedback controller of the voice coil motor at low frequencies. Although the voice coil motor control loop becomes unstable, the micro-actuator stabilizes the entire feedback loop at high frequencies. As a result, the control system improves the positioning accuracy compared to that achieved by conventional control methods, and the required micro-actuator stroke is reduced.

scholarly journals An Infrastructure-Free Magnetic-Based Indoor Positioning System with Deep Learning

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6664
Author(s):  
Letícia Fernandes ◽  
Sara Santos ◽  
Marília Barandas ◽  
Duarte Folgado ◽  
Ricardo Leonardo ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Indoor Positioning ◽  
Test Dataset ◽  
Magnetic Field Data ◽  
Positioning Systems ◽  
Additional Information ◽  
Information Layer ◽  
Wide Range ◽  
Indoor Positioning System ◽  
New Infrastructure

Infrastructure-free Indoor Positioning Systems (IPS) are becoming popular due to their scalability and a wide range of applications. Such systems often rely on deployed Wi-Fi networks. However, their usability may be compromised, either due to scanning restrictions from recent Android versions or the proliferation of 5G technology. This raises the need for new infrastructure-free IPS independent of Wi-Fi networks. In this paper, we propose the use of magnetic field data for IPS, through Deep Neural Networks (DNN). Firstly, a dataset of human indoor trajectories was collected with different smartphones. Afterwards, a magnetic fingerprint was constructed and relevant features were extracted to train a DNN that returns a probability map of a user’s location. Finally, two postprocessing methods were applied to obtain the most probable location regions. We asserted the performance of our solution against a test dataset, which produced a Success Rate of around 80%. We believe that these results are competitive for an IPS based on a single sensing source. Moreover, the magnetic field can be used as an additional information layer to increase the robustness and redundancy of current multi-source IPS.

Expected Values of Wave Power Absorption Around the Japanese Islands Using OWC Types With Projecting Walls

2011 ◽  
Author(s):  
Tomoki Ikoma ◽  
Hiroyuki Osawa ◽  
Koichi Masuda ◽  
Hiisaaki Maeda
Keyword(s):  
Resonance Frequency ◽  
Performance Improvement ◽  
Standing Waves ◽  
Wave Power ◽  
Basic System ◽  
Oscillating Water Column ◽  
Power Absorption ◽  
Wide Range ◽  
Expected Values ◽  
Japanese Islands

This paper describes performance improvement of wave power absorption by using a new concept. Basic system proposed is an oscillating water column (OWC) type. An artificial harbor surrounded by projecting walls is installed. The type is called as PW-OWC in this paper. Standing waves occur in the artificial harbor, the absorbing device consequently has a resonance frequency differing from that of OWC. From the effect, the system is able to absorb wave power in very wide range of the wave frequency. From the experimental results, PW-OWC types are very good performance of wave power absorption comparing with conventional OWC types. In addition, the performance of the PW-OWC type is insensibility to the nozzle ratio of an orifice. The performance can be easily improved by installing the harbor part even if the performance of a base OWC device is not good. Finally, we investigate the expected values of acquirable wave power in not only a year but also every season. The expected values of PW-OWC types are greater than that of conventional OWC ones in seas around the Japanese islands.

Spatial Filter Design for Dual-Stage Systems

2017 ◽  
Author(s):  
Aleksandra Mitrovic ◽  
Kam K. Leang ◽  
Garrett M. Clayton
Keyword(s):  
Long Range ◽  
High Speed ◽  
Filter Design ◽  
Spatial Filter ◽  
Control Allocation ◽  
Clear Understanding ◽  
Positioning Systems ◽  
Significant Research ◽  
Dual Stage ◽  
Increasing Demand

Increasing demand for high precision positioning systems has motivated significant research in this field. Within this field, dual-stage nanopositioning systems have the unique potential to offer high-speed and long-range positioning by coupling a short-range, high-speed actuator with a long-range, low-speed actuator. In this paper, design considerations for a spatial filter are presented. The spatial filter allows for control allocation based on range of the signal as opposed to more commonly used frequency-based control allocation. In order to understand the spatial filtering approach more fully, this paper analyzes the filter in detail to understand limitations and give the user a more clear understanding of the approach. Simulation results are included to illustrate aspects of the discussion.

scholarly journals Introducing a Cost-Effective Approach for Improving the Arterial Traffic Performance Operating Under the Semi-Actuated Coordinated Signal Control

2018 ◽  
Vol 2672 (18) ◽  
pp. 71-80 ◽  
Author(s):  
Sina Dabiri ◽  
Kianoush Kompany ◽  
Montasir Abbas
Keyword(s):  
Operation Mode ◽  
Cost Effective ◽  
Adaptive Controller ◽  
Signal Control ◽  
Significant Variable ◽  
Average Delay ◽  
Traffic Demand ◽  
Cost Effective Approach ◽  
Wide Range ◽  
Optimal Value

The semi-actuated coordinated operation mode is a type of signal control where minor approaches are placed with detectors to develop actuated phasing while major movements are coordinated without using detection systems. The objective of this study is to propose a cost-effective approach for reducing delay in the semi-actuated coordinated signal operation without incurring any extra costs in terms of installing new detectors or developing adaptive controller systems. We propose a simple approach for further enhancing a pre-optimized timing plan. In this method, the green splits of non-coordinated phases are multiplied by a factor greater than one. In the meantime, the amount of green time added to the non-coordinated phases is subtracted from the coordinated phases to keep the cycle length constant. Thus, if the traffic demand on the side streets exceeds the expected traffic flow, the added time in the non-coordinated phase enables the non-coordinated phases to accommodate the additional traffic demand. A regression analysis is implemented so as to identify the optimal value of the mentioned factor, called actuated factor (ActF). The response variable is the average delay reduction (seconds/vehicle) of the simulation runs under the proposed signal timing plan compared with the simulation runs under the pre-optimized timing plan, obtained through the macroscopic signal optimization tools. External traffic movements, left-turn percentage, and ActF are the explanatory variables in the model. Results reveal that the ActF is the only significant variable with the optimal value of 1.15 that is applicable for a wide range of traffic volumes.

Dynamic Modeling and Control of a Piezo-Electric Dual-Stage Tape Servo Actuator

2008 ◽  
Author(s):  
Uwe Boettcher ◽  
Bart Raeymaekers ◽  
Raymond A. de Callafon ◽  
Frank E. Talke
Keyword(s):  
Low Frequency ◽  
Voice Coil Motor ◽  
Step Response ◽  
Time Model ◽  
Modeling And Control ◽  
Micro Actuator ◽  
Single Output ◽  
Lateral Tape Motion ◽  
Dual Stage ◽  
Dual Stage Actuator

We have implemented the design of a dual-stage actuator tape head for enhanced reduction of lateral tape motion (LTM) disturbance. Our design consists of a conventional voice coil motor (VCM) and a micro-actuator for coarse and fine positioning, respectively. The micro-actuator, which is mounted on the VCM, uses a piezo crystal and allows following LTM up to the kHz regime, while the VCM follows low frequency LTM. Using step response measurements and a realization algorithm, we have created a multi-input discrete-time model of the dual-stage actuator. Based on the model, we designed and implemented a dual-stage controller, using a dual-input single-output approach based on a PQ method. The dual-stage controller controls the position of both actuators and enables an increased track-following bandwidth along with a control signal that is smaller in magnitude than that for a conventional single-stage tape head.

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