Pair Of Actuators Research Articles

Thermally actuated micro-/nanoscale deformations for optical reconfigurations

The unique three-dimensional (3D) deformations caused by nano-kirigami have enabled a new degree of freedom for reconfigurable optics. Here, we demonstrate a facile nano-kirigami method that can create 3D deformed structures, which can flexibly manipulate optical properties using thermally actuated micro-/nanoscale deformations. By connecting four pairs of thermal actuators to the four sides of a gradient metasurface, large-angle beam steering (∼90°) can be achieved by adjusting the temperature of the actuators. The amplitude of circular dichroism can be adjusted by thermally actuating micro-/nanoscale deformations. The 2D-to-3D transformation of the curved arm structure on metallic substrate results in enhanced structural absorption, inducing an almost perfect absorption at specific wavelengths. Curved asymmetric structures can also be created by thermally actuated micro-/nanoscale deformations, which provides a novel method for cross-polarized light conversion. The proposed design with thermally actuated micro-/nanoscale deformations provides a new methodology to explore versatile reconfigurable functionalities.

Numerical simulation of the flow around a square cylinder under plasma actuator control

Navier–Stokes computations are performed, and detailed results are documented on the vortex shedding, lift and drag fluctuations, and their spectra for flow past a square cylinder with the Reynolds number ranging from 1 to 300. A body force model for the dielectric barrier discharge (DBD) plasma actuator is used in the Navier–Stokes computations to study the effectiveness of flow control by a pair of the DBD actuators. Three installation configurations of the actuators are investigated. The effects of the actuator location, actuator input power, and the flow Reynolds number are studied. In the first case, two actuators have been installed on the top and bottom of the cylinder. In the second case, two actuators are installed on the front surface. In the last case, two actuators are installed on the rear surface. It is discovered that the best flow control effect is achieved in the last case. Both the unsteady vortex shedding and the average drag can be significantly reduced by the plasma actuators. Under best conditions, the vortex shedding in the wake can be completely suppressed.

Light-Driven Linear Inchworm Motor Based on Liquid Crystal Elastomer Actuators Fabricated with Rubbing Overwriting.

Linear displacement is used for positioning and scanning, e.g., in robotics at different scales or in scientific instrumentation. Most linear motors are either powered by rotary drives or are driven directly by pressure, electromagnetic forces or a shape change in a medium, such as piezoelectrics or shape-memory materials. Here, we present a centimeter-scale light-powered linear inchworm motor, driven by two liquid crystal elastomer (LCE) accordion-like actuators. The rubbing overwriting technique was used to fabricate the LCE actuators, made of elastomer film with patterned alignment. In the linear motor, a scanned green laser beam induces a sequence of travelling deformations in a pair of actuators that move a gripper, which couples to a shaft via friction moving it with an average speed in the order of millimeters per second. The prototype linear motor demonstrates how LCE light-driven actuators with a limited stroke can be used to drive more complex mechanisms, where large displacements can be achieved, defined only by the technical constrains (the shaft length in our case), and not by the limited strain of the material. Inchworm motors driven by LCE actuators may be scaled down to sub-millimeter size and can be used in applications where remote control and power supply with light, either delivered in free space beams or via fibers, is an advantage.

Improving the mixing of a turbulent jet diffusion flame of methane via linear quadratic regulator control

The purpose of this article is to show the improvement of the mixture of a turbulent jet diffusion flame of methane by means of linear quadratic regulator control. The model is based on low Mach and high Damköhler numbers. Large eddy simulation is used to simulate a turbulent flow with the Smagorinsky submodel for turbulent viscosity. The control employs a pair of actuators that act transversally to the flow direction on the walls of the burner. They consist of rectangular openings added along the depth of the duct. Numerical tests were performed by changing the position of one of these actuators. The results show that the controllers alter the jet diffusion flame, generating vortices of different sizes and dispersion patterns, which quickly leads to highly complex flow patterns.

Bypass transition in a boundary layer flow induced by plasma actuators

Bypass transition in flow over a flat plate triggered by a pair of dielectric-barrier-discharge plasma actuators mounted on the plate surface and aligned in the streamwise direction is investigated. A four-species plasma–fluid model is used to model the electrohydrodynamic force generated by the plasma actuation. A pair of counter-rotating streamwise vortices is created downstream of the actuators, leading to the formation of a high-speed streak in the centre and two low-speed streaks on each side. As the length of actuators increases, more momentum is added to the boundary layer and eventually a turbulent wedge is generated at an almost fixed location. With large spanwise distance between the actuators (wide layout), direct numerical simulations indicate that the low-speed streaks on both sides lose secondary stability via an inclined varicose-like mode simultaneously, leaving a symmetric perturbation pattern with respect to the centre of the actuators. Further downstream, the perturbations are tilted by the mean shear of the high- and low-speed streaks and consequently a ‘W’-shaped pattern is observed. When the pair of plasma actuators is placed closer (narrow layout) in the spanwise direction, the mean shear in the centre becomes stronger and secondary instability first occurs on the high-speed streak with an asymmetric pattern. Inclined varicose-like and sinuous-like instabilities coexist in the following breakdown of the negative streaks on the side and the perturbations remain asymmetric with respect to the centre. Here the tilting of disturbances is dominated by the mean shear in the centre and the perturbations display a ‘V’ shape. Linear analysis techniques, including biglobal stability and transient growth, are performed to further examine the fluid physics; the aforementioned phenomena at narrow and wide layouts, such as the secondary instabilities, the ‘V’ and ‘W’ shapes, and the symmetric and asymmetric breakdown, are all observed.

Motion planning of a fish-like piezoelectric actuated robot using model-based predictive control

This work proposes a novel methodology for planning the motion of fish-like soft robots actuated by macro-fiber composite (MFC) pairs. These structures should mimic oscillatory and undulation movements, which can be accomplished if the amplitude of the tail motion is larger than that of the head motion. Design strategies, such as the use of concentrated and distributed masses, are addressed to mimic fish-like motion since they guarantee suitable mode shapes for the structure. The motion planning proposal explores a model-based predictive control (MPC) strategy for deriving the input signals for the MFC actuators. This model-based control strategy requires the use of reasonably small-sized models. This is accomplished by extracting modal state-space models based on the free–free Euler–Bernoulli beam theory considering the electro-mechanical coupling of the MFC actuator pairs. Numerical results demonstrate the capability of the proposal for deriving bounded input signals that generate oscillatory and undulation movements even in the presence of disturbances. This general approach can be further extended for other applications.

A MEMS Optical Phased Array Based on Pitch Tunable Silicon Micromirrors for LiDAR Scanners

This paper presents the design, modeling, fabrication, and testing of an optical phased array (OPA) based scanner utilizing microelectromechanical system (MEMS) micromirrors with in-plane pitch tuning capability for high-speed and high-resolution laser beam steering. A pair of lateral comb-drive actuators are located at both sides of the free-standing structure of the micromirror array and used to generate the force required for in-plane motion of the micromirrors. Identical folded-beam flexures on both sides of the moving part of each comb-drive actuator allow for the precisely guided lateral motion and reduction of the in-plane mechanical stiffness. The mirror-positioned flexures enable a symmetrical structure which helps to reduce side instability as well as levitation during lateral comb-drive actuation. Analytical models of the OPA structure are presented for estimations of the micro actuator performance as well as the optical characteristics. A prototype for the proposed OPA system with polysilicon as structural material and gold as optically reflective surface is fabricated using a surface micromachining process. The optical path difference is realized by slightly elevating every other micromirrors along the array in order to form the required optical phase shift. The aperture size of the OPA based scanner is about <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$195\,\,\mu \text{m}\,\,\times 185\,\,\mu $ </tex-math></inline-formula> m and the fill factor of the array is 40-57%. Pitch tuning due to the electrostatic actuation results in an optical steering range of 0.06° with angular resolution of 0.002° at 30 V and a laser wavelength of 650 nm. [2021-0070]

Modified PID like fuzzy servo control applied to smart actuator based miniature Parallel Robot

Miniature flexible parallel robots, popularly used for micro positioning application demands the use of non conventional actuators. Shape memory alloys (SMA) are popular smart actuators because of its light weight, integration compatibility, ease of actuation and high power density. Inclusion of shape memory alloy actuators to the parallel robot brings in control challenges due to its nonlinearity, coupling effects and cocontraction of antagonistic pair of actuators in the mechanism in order to achieve bi directional motion. In this paper, a PID like fuzzy controller is designed and applied to a nonlinear SMA spring actuator connected to a symmetric 2 DOF miniature parallel robot. The fuzzy rules are designed from the general response plot and modified to be applied to a parallel mechanism which involves cocontraction of antagonistic actuators. The paper has also presented the control and electrical circuit design used in the experimental set up. The fuzzy control is implemented in the hardware controller with model based position feedback and tested for the trajectory tracking characteristics of the end effector with disturbances. Experimental results are presented with quantitative analysis to show the effectiveness of the proposed controller in handling nonlinearities and disturbances compared to the conventional PID control and nonlinear Sliding mode control (NSMC). The test results has demonstrated the superior nature of proposed control over other controllers in the trajectory tracking with disturbances and also linearizing the hysteresis of controlled system.

Anguilliform Swimming Performance of an Eel-Inspired Soft Robot.

In this article, we propose a soft eel robot design using soft pneumatic actuators that mimic eel muscles. Four pairs of soft actuators are used to construct the eel robot body. Pulse signals with suitable shifting phases are utilized to control delivery of compressed air to the actuators in sequence to create a sinusoidal wave from head to tail of the robot body. A model of hydrodynamic forces acting on an anguilliform swimmer when moving in fluid was built to estimate the thrust force generated by the robot at different tail beat frequencies. Experimental data revealed that the generated thrust force was positively correlated with the beat frequency. Measured data showed that swimming efficiency depended on both generated thrust force and body posture in situ. At the beat frequency of 1.25 Hz, and air pressure at three segments from head to tail of 65, 50, and 30 kPa, respectively, the eel robot body showed the best cost of transport (COT) of 19.21 with velocity of 10.5 cm/s (or 0.198 body length per second [BL/s]), compared to the other's values of operation frequency and air pressure. We also found that control shifting phase strongly affects the swimming speed and COT. The robot body reached the highest velocity at around 19 cm/s (0.36 BL/s) with the COT of 10.72. Obtained result in this research would contribute to development of soft elongated swimming robot and enhance the knowledge on swimming performance of both robot and natural eels.

Heat transfer enhancement through a rectangular channel by DBD plasma actuators as vortex generators

This paper represents a three-dimensional numerical simulation to figure out the application of the DBD plasma actuators as an active vortex generator system to enhance heat transfer through a smooth rectangular channel. This system as an active flow control device consists of a pair of DBD plasma actuators, which have been implemented asymmetrically on the bottom wall by several angles of attack to induce the cross airflow. The investigation deals with the optimum angle of attack according to different Reynolds number (Re) ranging from 2300 to 3800 and alternating current voltages of 31–37 kV. The heat transfer rate, pressure drop, and overall performance have been assessed. The results show the optimum choice for the angles of attack was 30° among various flow conditions. By this design, at the voltage of 37 kV and Re of 2300, the average Nusselt number (Num) increased about 56% and heat transfer performance factor ( $$\eta$$ ) increased about 111%. Furthermore, at the lowest applied voltage (31 kV) and highest Reynolds number (3800), the value of Num rises to 41% and 59%, respectively. Thereupon, as the next optimum choices, angle of attack of 45° at high Re and angle of attack of 15°at low Re enhanced heat transfer performance.

Bio-Inspired Haptic Feedback for Artificial Palpation in Robotic Surgery.

Adding haptic feedback has been reported to improve the outcome of minimally invasive robotic surgery. In this study, we seek to determine whether an algorithm based on simulating responses of a cutaneous afferent population can be implemented to improve the performance of presenting haptic feedback for robot-assisted surgery. We propose a bio-inspired controlling model to present vibration and force feedback to help surgeons localize underlying structures in phantom tissue. A single pair of actuators was controlled by outputs of a model of a population of cutaneous afferents based on the pressure signal from a single sensor embedded in surgical forceps. We recruited 25 subjects including 10 expert surgeons to evaluate the performance of the bio-inspired controlling model in an artificial palpation task using the da Vinci surgical robot. Among the control methods tested, the bio-inspired system was unique in allowing both novices and experts to easily identify the locations of all classes of tumors and did so with reduced contact force and tumor contact time. This work demonstrates the utility of our bio-inspired multi-modal feedback system, which resulted in superior performance for both novice and professional users, in comparison to a traditional linear and the existing piecewise discrete algorithms of haptic feedback.

Nonlinear modeling of [formula omitted]-mode piezoelectric actuators using experimental vibration analysis

This article focuses on characterizing the nonlinear nature of the piezoelectric actuators’ ‘33’-electromechanical coupling and ‘3’-directional elasticity. Vibrations of a cantilever aluminum beam, attached with a pair of d33-mode surface bondable multilayer actuators, were studied to construct the required nonlinear constitutive equation. As both elasticity and electromechanical coupling were of equal interest, a sequential experimental procedure was followed to conduct an exclusive analysis of each of them. Accordingly, first, the actuators were short-circuited, and a set of displacement-frequency-response plots were obtained for the first and second bending modes. The profile of the backbone curve of the response plots revealed the presence and the nature of the nonlinearity in the elastic domain. Equipped with the knowledge of the nonlinear elastic behavior, nonlinearity in electromechanical coupling was then investigated from a set of response plots obtained through the piezoelectric actuation of beam. Here too, the profile of the backbone curves revealed the type of nonlinearity present in the electromechanical behavior. With the information obtained from these two steps, a final nonlinear constitutive equation was constructed to represent both the nonlinear elasticity and the nonlinear electromechanical coupling in the actuator.

An intubation catheter integrated with flow sensors and smart actuators for characterizing airflow patterns in stenosed trachea: an objective guide for CAO management

Stenosis reduces the effective lumen area in the tracheal and bronchial segments of the airway anatomy. Loss in patency due to obstruction increases resistance to airflow; thus, severe narrowing is often associated with morbidity and mortality. Etiologies such as congenital tracheal stenosis, tracheomalacia, laryngeal and subglottic stenosis, atresia are few among the many pathologies causing major airway obstruction and respiratory distress. Diagnosis of such anomalies is usually based on clinical suspicion due to the non-specificity of the associated clinical symptoms. Visual assessment using conventional bronchoscopy or radiography images from CT scan for precisely locating obstruction site is highly subject to clinician’s expertise. Characterizing airflow patterns in stenosed airway calls for newer diagnostic tools that can effectively quantify changes in airflow due to construction sites. Our work presents a steerable intubation catheter that can quantitatively measure air velocity across various segments of the tracheobronchial tree. The catheter consists of a three-layer flexible printed circuit board integrated with micro-electro-mechanical system-based thermal flow sensors and a pair of sub-millimeter helical shape memory actuators. Flow distribution is measured in excised sheep tracheal tissues at 15, 30, 50, 65, and 80 l min−1 for normal and stenosed conditions. Even a 10% reduction in lumen area generated unique peaks corresponding to the obstruction site; thus, the catheter can locate stenosis at the precritical stage. For 50% tracheal obliteration, the sensor closest to stenosis showed a 2.4-fold increase in velocity when tested for reciprocating flows. Thus, flow rate scales quadratically with reducing cross-section area, contributing to increased airflow resistance.

Large-scale testing facility for heavy haul track

Given the substantially increased demand for increased axle loads of heavy haul trains, there is an imperative need to develop sustainable track infrastructure. When subjected to heavy axle loading, ballast aggregates rapidly break down, compromising the particle friction and associated load bearing capacity. Therefore, understanding the deformation and degradation (breakage) of ballast subjected to various boundary and loading conditions is crucial for improved track design and performance monitoring. Ideally, field testing should be carried out in real-life tracks to avoid laboratory scale and boundary effects, but field tests are often expensive, time-consuming and may disrupt rail traffic, hence not always feasible. A prototype test facility that can simulate appropriate axle loading and boundary conditions for standard gauge heavy haul tracks is presented in this paper. In collaboration with more than a dozen Universities and Industry organisations, Australia's first and only National Facility for Heavy-haul Railroad Testing (NFHRT) has recently been constructed and is now fully operational. This new facility enables a real-size (1:1 scale) instrumented track section to be subjected to continuous cyclic loading simulated via two pairs of dynamic actuators in synchronized operation. The results of a typical test are presented in this paper including the measured track settlement and lateral deformation, transient vertical and lateral stresses, rail and sleeper accelerations, resilient modulus and breakage of ballast. The test results show that an average track settlement of about 14 mm and lateral displacements up to 9 mm are recorded after 500,000 load cycles. Subjected to a 25-tonne axle load, the maximum vertical stress measured at the sleeper-ballast interface is about 225 kPa and this attenuates with depth. The test results of this iconic facility are generally consistent with actual field measurements obtained in heavy-haul tracks located in the towns of Singleton and Bulli in the state of New South Wales, Australia.

Retracted] SAP: An IoT Application Module Placement Strategy Based on Simulated Annealing Algorithm in Edge‐Cloud Computing

The Internet of Things (IoT) is rapidly growing and provides the foundation for the development of smart cities, smart home, and health care. With more and more devices connecting to the Internet, huge amounts of data are produced, creating a great challenge for data processing. Traditional cloud computing has the problems of long delays. Edge computing is an extension of cloud computing, processing data at the edge of the network can reduce the long processing delay of cloud computing. Due to the limited computing resources of edge servers, resource management of edge servers has become a critical research problem. However, the structural characteristics of the subtask chain between each pair of sensors and actuators are not considered to address the task scheduling problem in most existing research. To reduce processing latency and energy consumption of the edge‐cloud system, we propose a multilayer edge computing system. The application deployed in the system is based on directed digraph. To fully use the edge servers, we proposed an application module placement strategy using Simulated Annealing module Placement (SAP) algorithm. The modules in an application are bounded to each sensor. The SAP algorithm is designed to find a module placement scheme for each sensor and to generate a module chain including the mapping of the module and servers for each sensor. Thus, the edge servers can transmit the tuples in the network with the module chain. To evaluate the efficacy of our algorithm, we simulate the strategy in iFogSim. Results show the scheme is able to achieve significant reductions in latency and energy consumption.

State-Space Modeling and Active Vibration Control of Smart Flexible Cantilever Beam with the Use of Finite Element Method

The aim of this study is to design a Linear Quadratic Regulator (LQR) controller for the active vibration control of a smart flexible cantilever beam. The mathematical model of the smart beam was created on the basis of the Euler-Bernoulli beam theory and the piezoelectric theory. State-space and finite element models used in the LQR controller design were developed. In the finite element model of the smart beam containing piezoelectric sensors and actuators, the beam was divided into ten finite elements. Each element had two nodes and two degrees of freedom were defined for each node, transverse displacement, and rotation. Two Piezoelectric ceramic lead Zirconate Titanate (PZT) patches were affixed to the upper and lower surfaces of the beam element as pairs of sensors and actuators. The location of the piezoelectric sensor and actuator pair changed and they were consecutively placed on the fixed part, the middle part, and the free end of the beam. In each case, the design of the LQR controller was made considering the first three dominant vibratory modes of the beam. The effect of the position of the sensor-actuator pair on the beam on the vibration damping capability of the controller was investigated. The best damping performance was found when the sensor-actuator pair was placed at the fixed end.

Multi-link endoscopic manipulator robot actuated by shape memory alloys spring actuators controlled by a sliding mode

The aim of this study was to design and evaluate a prototype of a snake-like endoscopic manipulator robot (SLEMR) and its corresponding automatic controller based on the first order sliding mode theory. The SLEMR was controlled with a set of actuators made of shape memory alloys (SMA). The SLEMR device was constructed with a sequential arrangement of links interconnected by a two degree-of-freedom joint. A parallel agonist–antagonist configuration of actuators was implemented to move each joint. The physical relation between temperature and elongation in SMA forced the execution of the movement in the joint. Elongation–temperature model of the SMA actuator served to get a feasible bound of velocity for each joint. Each pair of SMA actuators was controlled by a first order sliding mode controller. This control design solved the tracking trajectory problem for each joint in the SLEMR because of its robustness against uncertainties and external perturbations. The control action was projected into a feasible implementable set of pulse-width modulated signals which was used to regulate the temperature of the corresponding SMA actuator. The controller designed in this study was experimentally validated in a SLEMR made up by a tridimensional printing technique. The control strategy induced the successful trajectory tracking for all the joints in the SLEMR simultaneously. This characteristic of the control design also enforces the tracking of a reference position by the tip of the final link of the SLEMR. An image acquisition system was used to determine the position of the final actuator in the SLEMR. The effectiveness of the controller proposed in this study was confirmed by the evaluation of the tracking error of the final actuator which approached to a bounded region (less than 1.0 mm) near the origin in a finite-time (0.5 s).

Modelling of smart intelligent materials with PZT & PVDF sensors/actuators to control the active vibrations of flexible aluminum mechanical cantilever beams using proportional integral derivative (PID) techniques

Modelling of smart intelligent materials with PZT & PVDF sensors / actuators to control the active vibrations of flexible aluminum mechanical cantilever beams using PID techniques is presented in this research article. A multi input multi output beam (flexible cantilever beam) is considered as the single point of attraction and this is the plant, which is to be subjected to the vibrations, this could be treated as the wing of an aircraft attached to the hub. The flexible mechanical aluminium cantilever beam is subjected to vibrations, say an external force being acted upon by the wind pressure or an exciter. Smart materials have got some special properties that react to the changes in their environmental conditions. The beam is subjected to vibrations. These vibrations should be suppressed in no time, else, the plant may get damaged. Hence, we put piezoelectric (PZT) and poly vinyl derylene fluoride (PVDF) sensor and actuators at 2 different positions to sense the vibrations and act upon immediately to neutralize it. The PZT sensors sense the vibrations & the actuators give an actuating signal to the controller, which in turn generates anti signals to neutralize the effect of the primary source of vibration. We have used the multi-sensor data fusion concept as if we use the same sensor and actuator, we may not get good results. Mathematical modelling of sensor and actuators of the 2 types is done, this is used to design the PID controller to suppress the vibrations in no time. The paper shows the effect of the multi sensor actuator pair of smart intelligent materials used in the vibration suppression. The work done can also compared with others to show the authenticity or the profoundness of the methodology proposed with the help of materials used in the theory of material science.

Use of smart intelligent sensor & actuator mechanical materials (PVDF / PZT) in developing MIMO mathematical model of the smart structure and its use to control the active vibrations using discrete sliding mode control theory with output samples

A multi-input, multi-output based modelling of intelligent flexible mechanical aluminium structures using smart materials with Euler-Bernoulli beam theory & state space techniques is being presented with multi-sensor data fusion concepts. An aluminium cantilever beam of rectangular cross section with known specifications is considered for the modelling purposes. To start with, from the fundamental principles of E-B theory, a Lagrange equation of motion is obtained both for the regular beam element as well as for the PZT & PVDF sensor actuator pair. Following which, a dynamic equation of motion of the smart intelligent structure developed using the smart materials consisting of PZT& PVDF is obtained. The dynamic equation is transformed into a state space model with 2 i/o’s using the concepts of state space theory in control engineering. The model is developed considering the first 2 modes of vibration, which are the most dominant modes in the vibration theory. The developed state space model is used for active vibration control. An external force of 1 N is applied at the end of the smart flexible multivariable multimodel cantilever beam after which the beam is subjected to vibrations. A Discrete Sliding Mode Control (DSMC) based controller on the o/p samples is designed and put in loop with the plant, after which the plant vibrations decays to zero in no time. The mathematical model of the DSMC controller is used to control the vibrations of the plant using the concept of destructive interference. The mathematical model of the DSMC controller can be used to control the vibrations of the plant using the concept of destructive interference.

Active tunability of band gaps for a novel elastic metamaterial plate

A novel active elastic metamaterial plate is proposed, with tunable vibration band-gap characteristics is by using the periodically placed piezoelectric actuator and sensor pairs along one direction of the plate. Active control strategies are employed to actively adjust the band-gap properties of the metamaterial plate. Displacement and acceleration feedback control methods are applied to design the controllers so that the positive active stiffness and inertia for the elastic metamaterial plate can be provided. The dynamic responses of the finite plate with periodic piezoelectric actuator/sensor pairs are calculated using the spectral element method (SEM), and the calculation accuracy of the SEM is validated by the finite element method. The present results reveal that zero-frequency band gaps can be generated for the elastic metamaterial plate, and the band-gap characteristics in the medium and high frequency ranges can be significantly enhanced by using the acceleration feedback control. Moreover, very wide band gaps for the elastic metamaterial plate can be obtained by using the active acceleration control, and the starting frequencies of the first band gap under the acceleration control can be reduced by increasing the acceleration control gain. The widths of the zero-frequency and Bragg-type band gaps for the elastic metamaterial plate can be amplified by increasing the displacement feedback control gain. The control voltages to be applied on the actuators for the elastic metamaterial plate are also calculated and discussed.