Actuator Effectiveness Research Articles

An Enhanced Time Delay Smith Predictor of Sliding Mode Structural Vibration Controller Based on Extended State Observer

Considering the total disturbances such as system time delay, model uncertainty, actuator effect and dynamic nonlinearities, a composite control strategy is proposed to suppress vibrations in an all-clamped plate structure, which combines sliding mode control based on extended state observer with time delay compensation (TDCSMCESO). First, a second-order state-space representation of the all-clamped plate, equipped with an inertial actuator, is formulated through the analysis of the dynamic partial differential equation and the physical model of the thin plate. Second, due to the inevitable system time delay and the noise amplification of the traditional differentiator, an enhanced differentiator is proposed to make the system without time delay. Additionally, a sliding mode control approach based on extended state observer (SMCESO) is designed to estimate and compensate for the total disturbance through a feedforward mechanism. Third, the closed-loop system’s stability is established through the application of the Lyapunov stability method. Finally, a semi-physical experimental platform utilizing an NI-PCIe6343 acquisition card and Matlab/Simulink environment is constructed to assess and compare the effectiveness of the proposed TDCSMCESO with SMCESO and traditional predictor-based SMCESO (PSMCESO). Comparative experiments show that the TDCSMCESO controller exhibits improved disturbance resistance and vibration reduction capabilities.

Methane/Air Flame Control in Non-Premixed Bluff Body Burners Using Ring-Type Plasma Actuators

Enhancing the combustion efficiency and flame stability in conventional systems is essential for reducing carbon emissions and advancing sustainable energy solutions. In this context, electrohydrodynamic plasma actuators offer a promising active control method for modifying and regulating flame characteristics. This study presents a numerical investigation into the effects of a ring-type plasma actuator positioned on the co-flow air side of a non-premixed turbulent methane/air combustion system—an approach not previously reported in the literature. The ring-type plasma actuator was designed by placing electrodes along the perimeter of the small diameter wall of the air duct. The impact of the plasma actuator on the reacting flow field within the burner was analyzed, with a focus on its influence on the flow dynamics and flame structure. The results, visualized through velocity and temperature contours, as well as flow streamlines, provide insight into the actuator’s effect on flame behavior. Two operating modes of the plasma actuators were evaluated: co-flow mode, where the aerodynamic effect of the plasma actuators was directed downstream; and counter-flow mode, where the effects were directed upstream. The findings indicate that the co-flow actuation positively reduces the flame height and enhances the flame anchoring at the root, whereas counter-flow actuation slightly weakens the flame root. Numerical simulations further revealed that co-flow actuation marginally increases the energy release by approximately 0.13%, while counter-flow actuation reduces the energy release by around 7.8%.

Experimental investigation of the effects of different DBD plasma actuators on the aerodynamic performance of the NACA0012 airfoil

Abstract This study aims to investigate the flow control performance of linear and serpentine dielectric barrier discharge (DBD) plasma actuators mounted on the leading edge of a NACA0012 airfoil to control flow separation and improve aerodynamic performance. Experiments were conducted in a subsonic wind tunnel at Reynolds numbers of 87 × 103, 131 × 103, and 175 × 103. Velocity profiles in the wake and static pressure distributions over airfoil were measured using hot-wire anemometry and pressure sensors, respectively. All experiments conducted in the different plasma actuation parameters, including wave voltages (6, 8, 10 kV) and wave frequencies (6, 10 kHz), and the optimal combination of V pp = 10 kV and f AC = 10 kHz was identified. The results of several wind tunnel experiments showed that, a substantial increase in the lift coefficient of up to 26.58% and a delay in stall angle of attack up to 4º due to the implementation of DBD plasma actuators. Additionally, the serpentine actuator demonstrated a more significant impact on separation control compared to the linear actuator where the serpentine actuator has controlled the stall phenomenon more effectively in post-stall angles compared to the linear actuator due to generation of 3D structures.

Numerical Investigation of the Coupling Effects of Pulsed H2 Jets and Nanosecond-Pulsed Actuation in Supersonic Crossflow

Numerical investigations were conducted to analyze the coupling effects of pulsed H2 jets and nanosecond-pulsed actuation (NS-SDBD) in a supersonic crossflow. The FVM was employed to solve the multi-component 2D URANS equations with the SST k-omega turbulence model, while H2-air combustion was described using a seven species–seven reactions chain reaction model, and the plasma thermal effect was represented by a phenomenological model. The backward-facing step flows with an inlet Mach number of 2.5 and a pulsed jet frequency of 10 kHz under different actuation conditions were simulated. The combustion enhancement mechanism under an actuation frequency of 20 kHz was analyzed. Research indicates that compression waves induced by NS-SDBD enhance H2-air mixing and facilitate temperature transport as the flow progresses. This progress is significantly associated with the flow structures generated by pulsed jets. Under this condition, the fuel utilization rate in the flow field increased by 61.2%, the total pressure recovery coefficient increased by 5.34%, and the outlet total temperature slightly increased even with a 50% reduction in fuel flow rate. Comparative analysis of different actuation cases demonstrates that evenly distributed actuation within the jet cycle yields better effects. The innovation of this study lies in proposing and exploring a potential method to address inadequate combustion under high-speed inflow conditions, which couples NS-SDBD with pulsed hydrogen jets.

Active alignment control system for thin disk regenerative amplifier.

We present an active alignment and stabilization control system for laser setups based on a thin-disk regenerative amplifier. This method eliminates power and pointing instability during the warm-up period and improves long-term stability throughout the entire operation. The alignment method is based on a four-mirror control system consisting of two motorized mirrors placed within the regenerative amplifier cavity, two additional motorized mirrors external to the amplifier cavity, and four camera detectors. The implemented stabilization system achieves significant performance improvements, increasing the power stability from 1.87% to 0.79% RMS and the peak-to-peak stability from 7.43% to 3.88%. Furthermore, the system significantly enhances beam positional stability, achieving up to a sixfold improvement in certain sensor measurements. The advantage of this method is the removal of long-term pointing instability by adding a second controlled motorized mirror to the cavity, in addition to using only one cavity end mirror for optimizing the overlap with the pump spot on the cavity medium. To achieve higher precision in pointing, the nonlinear hysteresis effect of the piezoelectric actuator is mitigated. Although the power and pointing stability of the cavity are secured, pointing instability at the input of the compressor occurs. This issue is resolved by two additional controlled motorized mirrors external to the cavity.

Magnetic Bistable Dome Actuators for Soft Robotics with High Volume Capacity and Motion Stability.

Magneto-responsive soft actuators hold significant promise in soft robotics due to their rapid responsiveness and untethered operation. However, controlling their deformations presents challenges because of their inherent flexibility and high degrees of freedom. Here, we present a magnetically driven bistable dome-shaped soft actuator that simplifies deformation by limiting it to two distinct states. The actuator achieves controlled state transitions by switching the orientation of external magnetic fields. We investigate the design strategy and magnetization styles of the dome-shaped soft actuator. Additionally, we analyze their effects on state transitions. The bistable dome undergoes significant volume changes reliably and smoothly during deformation, and its natural curvature makes it suitable for tasks involving rolling motion. We demonstrate the actuator's effectiveness in various applications, including an array of bistable domes for controlled actuation, a magnetically driven pulse pump with integrated check valves, and a ball-shaped bistable robot capable of efficient rolling locomotion and fluid manipulation. Our design significantly enhances the versatility and efficiency of bistable soft robotic systems, highlighting their potential for tasks such as liquid collection and release.

Fault-tolerant observer-based leader-following consensus control for LPV multi-agent systems using virtual actuators

This paper introduces a fault-tolerant consensus control approach for a continuous multi-agent system with actuator faults. The faults in the multi-agent system are modelled as additive and multiplicative actuator faults. The objective is to design a leader-following control for consensus-based Linear Parameter Varying (LPV) multi-agent systems. The proposed control approach employs a leader-following strategy, where the dynamics of the LPV virtual leader are defined. The synchronisation error between the followers and the virtual leader is considered, and a consensus control law is introduced. The fault-tolerant mechanism involves the design of a distributed LPV observer and an LPV virtual actuator. Fault-tolerance is achieved through the redistribution of control inputs based on the effectiveness of actuators and dynamic virtual actuators. The primary focus is on establishing Linear Matrix Inequalities (LMIs) conditions ensuring the existence of LPV consensus control, LPV observers, and LPV virtual actuator gains. To demonstrate the effectiveness of the proposed fault-tolerant control, simulation results considering a team of Unmanned Aerial Vehicles (UAVs) in formation under actuator faults are presented.

An MPC-based fault tolerant control of wind turbines in the presence of simultaneous sensor and actuator faults

In this paper, a fault-tolerant control structure is suggested in the full-load region of wind turbine systems to compensate for the effects of both actuator and sensor faults. This method is able to estimate all actual states of the system in finite time, and at the same time guarantee the fulfillment of all the parameter constraints. First, an MPC-based controller is designed in the full-load region to keep the output power in its rated value and hold the physical parameters in their allowed limitation. It is clear that any fault occurrence in the blade pitching actuators can make the output of the system away from its desired value. Furthermore, these types of faults can lead the system to instability and huge operating costs. To this aim, an additive control law based on a passive fault tolerant strategy is proposed to counteract the actuator faults. On the other hand, sensor faults and accurate estimation of the system’s actual states in finite time are the other challenges of wind turbine control systems. In this regard, an observer based on terminal sliding mode is developed to cope with sensor faults and estimate all actual states within a finite duration. It is shown that incorporating all proposed approaches leads the closed-loop system to be robust with significant performance.

The optimization of the actuator and sensor layout for piezoelectric smart blades

To reduce vibration-induced fatigue fractures of aero-engine blades, an active vibration control scheme for aero-engine blade has been developed proposed. In this paper, the Macro Fiber Composite (MFC) are used as actuators and sensors to suppress the vibration of the blade, but the position of the actuators and sensors has a great influence on the effectiveness of the blade vibration suppression. To achieve optimize suppress effect, the objective criterion for position optimization was proposed to be the absolute value normalized superposition of the strain of the first few natural frequency modes of the blade. First, a finite element analysis was conducted on the blade model. Then, the positions of the actuators and sensors were determined by using the differential evolution algorithm for optimization. The blade model with three layout strategies was constructed in ADAMS, and the ADAMS-Simulink joint simulation platform was constructed. Finally, the comparison of actuator and sensor effects with three position layout strategies is completed, the layout optimization strategy proposed in this paper achieves more significant vibration suppression with less control force was verified though the feedforward control experiments, and the effective of the proposed strategies are verified on the experimental platform for blade active vibration control.

Electrohydrodynamic characteristics of a needle-to-ring positive corona discharges: self-consistent modeling and turbulence effects

Abstract We report on the voltage–current characteristics as well as the voltage–velocity characteristics of a needle-to-ring configuration by self-consistent, 2D-axisymmetric, multi-physics plasma-fluid simulations. Parametric studies are performed to investigate the effects of background ionization level on the plasma electrical characteristics as well as turbulence parameters on the resulting flow. Our results show that the discharge and the flow exhibit an annular structure around the needle (anode) tip, with a maximum positive ion density from 1.5 × 10 18 –2.7 × 10 18 m − 3 and a maximum flow velocity from 10–15 m s − 1 , for overvoltages between 4−12 kV and an anode–cathode distance of 20 mm . Good overall agreement with experimental findings is achieved, noting that background ionization level can be used as a tuning parameter to better match experimentally measured current values even with a simplified plasma-chemistry. A better agreement between simulation and experiments is achieved concerning the voltage–velocity curves. Therefore, the latter are likely to be better indicators for assessing and validating electrohydrodynamic effects of corona actuators through numerical modeling. The flow dynamics indicate that positive-corona-induced ionic winds are most likely laminar to turbulent transitional flows, with a ratio between eddy viscosity and air viscosity varying between 0 − 200 .

Controlled entropy in tetra-hybrid nono-fluid helmholtz electroosmotic with motile germs via complex peristaltic pumping

Motile microorganisms, such as bacteria, can be engineered to transport medications directly to certain organs, such as cancer, tumors, enhancing drug efficacy and minimizing systemic side effects. These microorganisms can also be programmed to target and eliminate harmful bacteria, offering a novel approach to infection control. In parallel, functionalized nanomaterials show significant promise for precise manipulation of biological fluids. This focused approach improves drug efficacy while reducing systemic negative effects. Also, motile bacteria can be engineered to target and remove dangerous bacteria, providing a fresh approach to infection control. Nanomaterials with various functions show prodigious potential for precise operation of biological fluids. Tetra-hybrid nano-particles exhibit special electrical, optical, and thermal properties. They are composed of gold, silver, alumina, and titania. The streaming flow phenomena that result from the interactions of these nanocomposites with non-Newtonian biofluids, such as blood, can be studied using computational modeling. Considerations are made for forces such as non-Newtonian rheology, localized laser irradiation, and magnetohydrodynamics. Complex cellular trapping patterns are captured by predictions for temperature, velocity, and nanoparticle concentration profiles. Biocompatible multimodal nano-assemblies under magnetic actuation and thermos-plasmonic effects are used to exhibit precision biofluid control. To optimize, engineering parameters are visually analyzed. The unique features of tetra-hybrid nanoparticles, paired with motile microorganisms and non-Newtonian biofluid dynamics, allow for more precise therapeutic techniques, such as targeted medication administration and hyperthermia cancer treatment. By visualizing key engineering parameters, these findings highlight the potential for improved therapeutic strategies, such as targeted drug delivery and hyperthermia-based cancer treatments, enabled by the integration of tetra-hybrid nanoparticles and motile microorganisms in complex biofluid environments.

The development, characterisation and optimisation of bismuth ferrite (BFO)-incorporated Nafion membrane with comb-shaped inner structure as IPMC actuator for driving valveless micropump

Micropumps have become increasingly popular in biomedical devices due to their accurate, safe, and precise pharmaceutical administration. Ionic polymer-metal composites (IPMC) have shown great potential as diaphragm materials for micropump actuation. Redesigning the diaphragm shape can increase deformation by eliminating edge limitations in circular IPMC actuators. The present study demonstrates the application of inner cantilever-based (comb-shape) IPMC as actuation diaphragms in a micropump to enhance fluid movement. Furthermore, the effectiveness of an IPMC actuator is influenced by water absorption capacity, capacitance, and proton conductivity. To enhance the aforementioned characteristics, bismuth ferrite (BFO) was added to a Nafion matrix, resulting in a porous structure that increases capacitance. Moreover, the BFO-Nafion nanocomposite membrane exhibits a notably higher proton conductivity (0.1806 Scm−1) at a temperature of 30° C, in comparison to the normal Nafion 117 membrane (0.0254 Scm−1). The COMSOL Multiphysics and LASER Doppler Vibrometer are used to optimise the shape of the membrane and assess the IPMC’s electromechanical response. The deflection of the comb-shape geometries is around 171μm, surpassing existing membrane geometries. Finally, the drug delivery device prototype has a pump module, an Android-operated electronic control module, and an OLED display. This gadget achieves an insulin flow rate of 70 μL/min when operated at 3 V with a square wave frequency of 0.1 Hz. Moreover, the experimental findings indicate that applying an 8 V voltage resulted in a peak flow rate of 270 μL/min and a maximum back pressure of 140 Pascal.

A Randomized Controlled Trial to Compare the Effectiveness of Smart Dynamic Fabric Actuator with Exercises in Chronic Musculoskeletal Leg Pain Associated with Prolonged Standing in a Hospital Setting.

There are adverse effects on the health outcomes of workers whose occupation involves prolonged standing, such as lower back pain, leg pain, cardiovascular diseases, fatigue, discomfort, and pregnancy-related health outcomes. The effectiveness of massage therapy as an intervention for managing leg pain associated with prolonged standing needs to be addressed. This study aimed to evaluate the smart dynamic fabric actuator's effectiveness in treating chronic musculoskeletal leg pain in persons with occupations involving prolonged standing. Tertiary care hospital. Randomized controlled trial. Thirty participants with chronic leg pain satisfying the inclusion and exclusion criteria participated in the study. The intervention group used the device for 15 minutes for each leg once a day and stretching exercises twice a day for six weeks. The control group performed stretching exercises twice a day for six weeks. The outcome was assessed at baseline, three weeks, and six weeks with a Numeric Rating Scale for pain and fatigue, short form-McGill Pain Questionnaire for pain, and SF-36 for quality of life. The groups were compared using the two-sample t-test with equal variances, the two-sample Wilcoxon rank-sum test, and the Chi2 exact test as appropriate. Thirty medical (nursing officers and doctors) and nonmedical professionals (security guards and sales assistants) with a mean age of 32.9 ± 5.6 years (intervention group) and 36.2 ± 5.1 years (control group) participated in the study. At six weeks, a significant improvement in pain (4.80 ± 1.14 to 1.66 ± 1.04 vs 4.66 ± 0.89 to 2.6 ± 0.91, P = 0.014), quality of life (58.77 ± 9.06 to 71.76 ± 8.43 vs 51.39 ± 8.26 to 63.87 ± 7.61, P = 0.012), and reduced fatigue (5 to 2 vs 5 to 3, P = 0.003) was observed in the intervention group when compared with the control group. No adverse events were observed. A smart dynamic fabric actuator can be used as an adjunct to exercises for reducing leg pain and fatigue associated with prolonged standing.

Optimized design and performance testing of hydraulic electrostatic actuator

ABSTRACT Hydraulic electrostatic actuators have become a research hotspot for their inherent flexibility and safety of human-machine interaction. This paper aims to combine the characteristics of dielectric elastomers and fluid actuators, enhancing the dielectric constant and breakdown field strength by modifying Al2O3 on the surface of nanostructured BaTiO3 and in order to develop a hydraulic electrostatic actuator with silicone rubber as the matrix material. Single-factor experiments were firstly conducted to confirm the range of three factors affecting the actuation strain of the actuator: BaTiO3@Al2O3 content, thickness of the silicone rubber elastomer film, and pre-stretching ratio coefficient. The response surface methodology was used to study the interactive influence of the above three influencing factors on the actuation strain. It was obtained that A has an insignificant influence on the actuation strain, AB has a significant influence on the actuation strain, and B, C, AC, and BC have a highly influence on the actuation strain. Maximizing actuation strain as the optimization objective yielded the combination results of each factor: BaTiO3@Al2O3 content of 2.57%, thickness of 0.60 mm, and pre-stretching ratio coefficient of 2.50. Actuation strain tests were conducted with optimized parameters under no-load. The experimental results of the actuation strain test show that the relative error between the test value and the model prediction value of 16.47% is less than 5%, and the optimization model results are reliable. The optimized hydraulic electrostatic actuator was tested for actuation strain and electrical performance under different loads. The experiment showed that the maximum actuation strain of the hydraulic electrostatic actuator was 17.20% under a load of 100 g. The critical breakdown current of the actuator ranged from 115 μA to 130 μA, and the maximum electromechanical conversion efficiency of the actuator under different loads was 67.93%. Finally, a joint actuating device was developed based on the structure of the actuator, amplifying the output displacement of the actuator to 30 mm, and the linear displacement of the soft electro-fluid actuator can be converted into a 20° rotation angle through the gear steering mechanism, thus validating the effectiveness of the hydraulic electrostatic actuator.

Deformation and enclosed volume change of axisymmetric non-linear dielectric elastomer membrane pump: a theoretical study

Abstract This work investigates the change in the enclosed volume of an axisymmetric non-linear hyper-elastic membrane pump subjected to dielectric actuation. The equilibrium equations in cylindrical coordinates, coupled with non-linear constitutive relations, are solved numerically to obtain the deformed membrane geometry under pressure loading (using Variational Calculus). The effect of dielectric actuation is then incorporated by considering the change in material properties and deformation induced by the applied electric field. The deformed geometry under dielectric actuation is determined, and the change in enclosed volume is calculated by comparing the deformed states with and without the applied electric field. The proposed approach enables quantifying the volumetric change in non-linear hyper-elastic membrane pumps due to dielectric actuation for potential applications in soft robotics, adaptive optics, and microfluidics. By non-dimensionalizing variables, key dimensionless parameters governing the problem are identified for broader applicability. Furthermore, this methodology can estimate volume changes for different electric actuations when a specific material is chosen with experimentally derived parameter trends, facilitating material selection or synthesis to meet targeted volumetric requirements.

A PDMS/Silicon Adhesion Control Method at Millimeter‐Scale Based on Microvibration

Switchable surface adhesion at a small scale is crucial for robot end‐effector design, allowing the manipulation of small objects such as semiconductors, optical lenses, and precision mechanical parts. In this work, a detailed characterization of a millimeter‐scale (1–5 mm) adhesion modulation method is performed, demonstrating its effectiveness for switching adhesion on small, lightweight objects with smooth surfaces. This modulation phenomenon arises from the viscoelastic behavior when PDMS interacts with a rigid surface and is controlled via microvibration. A maximum apparent adhesion enhancement of 2400% and a reduction of 50% are achieved with a 1 mm‐diameter PDMS hemisphere vibrating at a 30 μm amplitude and a 700 Hz frequency. The effects of different parameters, including size, actuation amplitude/frequency, surface roughness, and material properties, on adhesion performance are carefully measured and analyzed. A monotonic increase in maximum adhesion is observed with increased device size and surface smoothness, while nonlinear relationships of other factors are generalized with a numerical model. A long working lifespan and high endurance are also observed during the characterization. This work serves as a practical reference for the further design of small‐scale soft grippers, highlighting its continuous, large modulation range, simple structure, and flexible control.

Triglobal resolvent-analysis-based control of separated flows around low-aspect-ratio wings

We perform direct numerical simulations of actively controlled laminar separated wakes around low-aspect-ratio wings with two primary goals: (i) reducing the size of the separation bubble and (ii) attenuating the wing tip vortex. Instead of preventing separation, we modify the three-dimensional (3-D) dynamics to exploit wake vortices for aerodynamic enhancements. A direct wake modification is considered using optimal harmonic forcing modes from triglobal resolvent analysis. For this study, we consider wings at angles of attack of $14^\circ$ and $22^\circ$ , taper ratios $0.27$ and $1$ , and leading edge sweep angles of $0^\circ$ and $30^\circ$ , at a mean-chord-based Reynolds number of $600$ . The wakes behind these wings exhibit 3-D reversed-flow bubble and large-scale vortical structures. For tapered swept wings, the diversity of wake vortices increases substantially, posing a challenge for flow control. To achieve the first control objective for an untapered unswept wing, root-based actuation at the shedding frequency is introduced to reduce the reversed-flow bubble size by taking advantage of the wake vortices to significantly enhance the aerodynamic performance of the wing. For both untapered and tapered swept wings, root-based actuation modifies the stalled flow, reduces the reversed-flow region and enhances aerodynamic performance by increasing the root contribution to lift. For the goal of controlling the tip vortex, we demonstrate the effectiveness of actuation with high-frequency perturbations near the tip. This study shows how insights from resolvent analysis for unsteady actuation can enable global modification of 3-D separated wakes and achieve improved aerodynamics of wings.

Study on the Vibration Reduction Effect of Piezoelectric Actuation on Flexible Tilting Pad Bearings with Different Structural Parameters

To improve the vibration performance of oil-lubricated tilting pad bearing systems, this paper investigates the impact of different structural parameters on the vibration reduction effect of piezoelectric actuators on flexible tilting pad bearings. Four sets of flexible tilting pad bearings were designed and manufactured, including a flexible hinge tilting pad bearing and three sets of double-layer spring-supported flexible tilting pad bearings with different parameters. The radial displacement of the bearing load pad was controlled to varying degrees using a piezoelectric actuator, and semi-active control experiments were conducted on the flexible tilting pad bearings. The experimental results show that appropriately reducing the radial clearance and the stiffness of the bearing’s flexible structure can effectively suppress vibrations, enhance the vibration reduction effect of the piezoelectric actuation, and increase the stability of the bearing-rotor system. This study is of significant importance for the design of flexible tilting pad bearings and the vibration suppression of rotor systems.

Model predictive control based integrated fault tolerant controller for autonomous vehicles with four-wheel independent steering, driving and braking systems

This paper presents a fault-tolerant control algorithm for path and velocity tracking of an autonomous vehicle based on four-wheel independent steering, driving, and braking systems. The proposed algorithm is designed to distribute the control effort to normal actuators in the occurrence of faults. The proposed algorithm consists of three modules. The reference velocity and yaw rate to track the reference path are determined by the reference state decision module. The model predictive control (MPC)-based fault-tolerant controller determines the optimal inputs to compensate for the effect of the faulty actuator and maintain the tracking performance. A faulty-factor estimator is proposed based on a recursive covariance estimator to evaluate the performance degradation due to the failure of each actuator. The estimated faulty factors are applied to the objective function of the MPC such that the control input is distributed based on the level of the fault. The performance of the proposed algorithm was verified via performing simulations using MATLAB/Simulink and CarSim. The simulations proved that the proposed controller maintained the control performance of the normal case even in multiple actuator failures.

Magnetically-Actuated Endoluminal Soft Robot With Electroactive Polymer Actuation for Enhanced Gait Performance

Abstract Endoluminal devices are indispensable in medical procedures in the natural lumina of the body, such as the circulatory system and gastrointestinal tract. In current clinical practice, there is a need for increased control and capabilities of endoluminal devices with less discomfort and risk to the patient. This paper describes the detailed modeling and experimental validation of a magneto-electroactive endoluminal soft (MEESo) robot concept that combines magnetic and electroactive polymer (EAP) actuation to improve the utility of the device. The proposed capsule-like device comprises two permanent magnets with alternating polarity connected by a soft, low-power ionic polymer-metal composite (IPMC) EAP body. A detailed model of the MEESo robot is developed to explore quantitatively the effects of dual magneto-electroactive actuation on the robot’s performance. It is shown that the robot’s gait is enhanced, during the magnetically-driven gait cycle, with IPMC body deformation. The concept is further validated by creating a physical prototype MEESo robot. Experimental results show that the robot’s performance increases up to 68% compared to no IPMC body actuation. These results strongly suggest that integrating EAP into the magnetically-driven system extends the efficacy for traversing tract environments.