- 标题
- 摘要
- 关键词
- 实验方案
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Opposite Self-Folding Behavior of Polymeric Photoresponsive Actuators Enabled by a Molecular Approach
摘要： The ability to obtain 3D polymeric objects by a 2D-to-3D shape-shifting method is very appealing for polymer integration with different materials, from metals in electronic devices to cells in biological studies. Such functional reshaping can be achieved through self-folding driven by a strain pattern designed into the molecular network. Among polymeric materials, liquid crystalline networks (LCNs) present an anisotropic molecular structure that can be exploited to tailor internal strain, resulting in a natural non-planar geometry when prepared in the form of flat films. In this article, we analyze the influence of different molecular parameters of the monomers on the spontaneous shape of the polymeric films and their deformation under different stimuli, such as heating or light irradiation. Modifying the alkilic chains of the crosslinkers is a simple and highly effective way to increase the temperature sensitivity of the final actuator, while modifying ester orientation on the aromatic core interestingly acts on the bending direction. Combining such effects, we have demonstrated that LCN stripes made of different monomeric mixtures originate complex non-symmetric deformation under light activation, thus opening up new applications in photonic and robotics.
关键词： photonic actuators,liquid crystalline networks,curvature design,photoresponsive polymers,shape-changing materials
更新于2025-11-21 11:24:58
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Simple Synthesis of Elastomeric Photomechanical Switches That Self-Heal
摘要： This article introduces a simple two-stage method to synthesize and program a photomechanical elastomer (PME) for light-driven artificial muscle-like actuations in soft robotics. First, photochromic azobenzene molecules are covalently attached to a polyurethane backbone via a two-part step-growth polymerization. Next, mechanical alignment is applied to induce anisotropic deformations in the PME-actuating films. Cross-linked through dynamic hydrogen bonds, the PMEs also possess autonomic self-healing properties without external energy input. This self-healing allows for a single alignment step of the PME film and subsequent “cut and paste” assembly for multi-axis actuation of a self-folded soft-robotic gripper from a single degree of freedom optical input.
关键词： stimuli-responsive,self-healing elastomers,soft robotics,photomechanical effects,actuators
更新于2025-09-23 15:23:52
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[SpringerBriefs in Applied Sciences and Technology] Vibration Analysis of Functionally Graded Piezoelectric Actuators ||
摘要： This book has evolved from the passionate desire of the author in using the modern concepts of piezoelectric materials for the design improvement of sensors and actuators. In this connection, the author took up his doctoral studies whose findings have resulted in this book. The initial focus here is on the basic theory, application, and drawbacks of piezoelectric materials. The types of deformation produced in piezoelectric materials due to different piezoelectric effects are reported briefly. Further, the concept of functionally graded material (FGM) used in the design of piezoelectric materials with graded properties is described. The engineering applications of functionally graded piezoelectric materials (FGPMs) are summarized thereafter. In the latter sections, the modal analysis of FGPM actuators is provided. Two types of actuator geometries are taken into consideration—first is beam, and the second is annular plate. The effects of various parameters on the natural frequencies are given in detail. A detailed account of a new numerical technique called the generalized differential quadrature (GDQ), adopted in this book, is also provided. An extension of this technique for the analysis of FGPM structures becomes an important endeavor. The overall focus is on the vibration analysis of FGPM actuators excited under the shear effect using the GDQ method.
关键词： Shear effect,Piezoelectric materials,Functionally graded materials,Vibration analysis,Actuators,Generalized differential quadrature method
更新于2025-09-23 15:23:52
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Multi-mode optimal fuzzy active vibration control of composite beams laminated with photostrictive actuators
摘要： Firstly, a multi-field coupling finite element formulation of composited beam laminated with the photostrictive actuators is developed in this paper. Moreover, an optimal fuzzy active control algorithm is also proposed on the basis of the combination of optimal control and fuzzy one. This method opens a new avenue to resolve the contradiction between the linear system control method and nonlinear actuating characteristics of photostrictive actuators. The desired control for suppressing multi-modal vibration of photoelectric laminated beam is firstly obtained through optimal control and then the fuzzy control is used to approach the desired mechanical strain induced by photostrictive actuators. Thus, the multi-mode vibration control of beam is realized. In the design process of optimal fuzzy controller, the design of fuzzy control is independent of optimal control. The simulation results demonstrate that the proposed control method can effectively realize multi-modal vibration control of photoelectric laminated beams, and the control effect of optimal fuzzy control is better than that of optimal state feedback control.
关键词： Multiple modes,Photostrictive actuators,Active control,Optimal fuzzy control algorithm,Finite element method
更新于2025-09-23 15:23:52
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Inversion-free force tracking control of piezoelectric actuators using fast finite-time integral terminal sliding-mode
摘要： The major hurdles to control the force created by piezoelectric actuators (PEAs) are originated from its strong nonlinear behaviors which include hysteresis, creep, and vibration dynamics. To achieve an accurate, fast and robust force tracking performance without using complicated modeling and parameter identification of PEAs, this paper presents a practical direct force control scheme. The proposed controller is based on two core approaches: 1) fast finite-time integral terminal sliding mode (FFI-TSM) which allows fast convergence and high accuracy to the closed-loop system without control chattering; and 2) an inverse-model-free compensation, named force-based time-delayed estimation (FBTDE) which offers significant robustness with minimum use of plant dynamics information. The finite-time stability of the overall closed-loop system is proven through the Lyapunov's method. The proposed force tracking controller is implemented on the PEA system driving a variable physical damping actuator mechanism. The overall accuracy, convergence speed, and robustness of the proposed controller are validated under various experimental scenarios. Comparative experimental results are particularly presented to verify the effectiveness of the FFI-TSM term and the FBTDE term.
关键词： Inversion-free force control,Piezoelectric actuators (PEAs),Time-delayed control (TDC),Terminal sliding mode
更新于2025-09-23 15:23:52
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A Large Range of Motion 3D MEMS Scanner With Five Degrees of Freedom
摘要： Here, we discuss a novel, mixed mode 3D XYZ scanner built within a single foundry process. The device has a large range of motion in X, Y, and Z (14.1 μm in X and Y and 97.9 μm in Z) and can also rotate about two axes (7.4°), making it a 5 degree of freedom scanner. Vertical actuation can be accomplished with both thermal actuators, which have a larger range of motion, and capacitive actuators, which are faster, responding fully up to 3.2 kHz. Although useful for many applications, including scanning probe microscopy, micrometer scale optical microscopy, and manipulation of biological objects, the device was designed to be a 3D scanner for spray-painting atoms upon a surface with nanoscale precision and resolution for nanofabrication. Demonstrating the ability to combine the device with other complicated MEMS systems, it is integrated with an XY scanner designed to serve as a shutter of atomic flux. The full system has 7 degrees of freedom and 12 actuation motors, and because it is built in a low cost commercial foundry with a robust and stable process, it is easy and inexpensive to fabricate multiple copies or integrate into other complicated systems, making a system of systems.
关键词： electrostatic actuators,thermal actuators,Comb drive,nanopositioning,position control,MEMS
更新于2025-09-23 15:22:29
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[SEMA SIMAI Springer Series] Recent Advances in Differential Equations and Applications Volume 18 || Optimal Design of Piezoelectric Microactuators: Linear vs Non-linear Modeling
摘要： The main point of this work is the comparison between linear and geometrically non-linear elasticity modeling in the field of piezoelectric actuators fabricated at the micro-scale. Manufacturing limitations such as non-symmetrical lamination of the structure or minimum length scale are taken into account during the optimization process. The robust approach implemented in the problem also reduces the sensitivity of the designs to small manufacturing errors.
关键词： Large displacements,Electrode profile,Piezoelectric actuators,Heterogeneous bimorph,Topology optimization
更新于2025-09-23 15:22:29
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Real-time Surface Shape Sensing for Soft and Flexible Structures using Fiber Bragg Gratings
摘要： In this paper, we present a new soft and flexible sensor which can reconstruct its surface shape in real-time. A single-core optical fiber with fiber Bragg gratings (FBGs) is capable of detecting sparse local strains at high bandwidth using wavelength-division multiplexing (WDM). The fiber was embedded into an elastomeric substrate to reconstruct its global surface morphology. Finite element analysis (FEA) was used to determine the design parameters, and also to validate the unique mapping from sparse strain measurements to the continuum shape of the sensor. To simplify the fabrication and error compensation process without precise/prior knowledge of the FBG locations in the sensor, machine learning-based modelling was applied. This enables real-time, robust and reliable shape reconstruction. It is demonstrated to outperform various applications of electronics-based sensors which require sophisticated electrode wiring and noise reduction. Experiments were performed to evaluate the sensing accuracy and repeatability.
关键词： Soft Sensors and Actuators,Flexible Robots,Surface Shape Sensing,Fiber Bragg Gratings
更新于2025-09-23 15:22:29
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Photoactive Functional Soft Materials (Preparation, Properties, and Applications) || Soft Materials Driven by Photothermal Effect and Their Applications
摘要： We are surrounded by soft materials. Most organs of the human body are made of soft materials. One defining characteristic of soft materials is that they can be readily deformed by external stimuli and stress. Even the thermal energy available at room temperature is sufficient to cause significant deformation in soft materials. de Gennes in his 1991 Nobel lecture emphasized “flexibility” as a defining characteristic of soft materials. Colloids, polymers, liquid crystals (LCs), gels, and biological materials are categorized as soft materials. Being pervasive in nature, soft materials have been a source of inspiration for scientists and engineers for the design and fabrication of stimuli‐responsive smart materials and systems for scientific investigations to understand the basic principles and technological application in devices and health care. Accordingly, a wide variety of engineered soft materials have been developed, which play a crucial role in modern technology. Soft nanotechnology, soft robotics, and soft lithography are examples that reflect the far‐reaching implications of soft materials in biology and engineering. Soft materials constitute one of the most stimulating interdisciplinary frontiers of modern science and are built on diverse experimental and theoretical foundations. Although soft materials in neat state have found a wide range of applications, fabrication of composites of soft materials by integrating other functional materials has recently become a common practice to realize advanced and tunable materials with enhanced properties for high‐tech applications. Incorporation of photothermal agents into the matrices of soft materials is one such emerging approach.
关键词： nanocomposites,soft materials,liquid crystals,photothermal therapy,polymers,gels,photothermal effect,actuators,drug delivery
更新于2025-09-23 15:21:01
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Photoactive Functional Soft Materials (Preparation, Properties, and Applications) || Photoresponsive Polyolefins
摘要： Nature is unmatched in its esthetics and precisely controlled complexity of biochemical structures of life and the way they function. Nature’s sophisticated functional hierarchical structures are mostly made from biopolymers like polypeptides and polysaccharides, which, over time, have evolved to respond to various adverse external stimuli at levels ranging from molecular to macroscopic. The responses include change of color, shape, porosity, and stiffness. The most commonly used synthetic commodity polymers are polyolefins. But, just as most known synthetic polymers, functional properties of polyolefins are static. The challenge is to develop a commercially viable stimuli‐responsive polymer material, based on commodity polymers such as polyolefins. If we can make it respond to external stimuli, like light, such photoresponsive materials will have a wide range of applications in optical storage, sensors, actuators, artificial muscle, and soft‐robotics, etc. This chapter will discuss briefly the photoresponsive polymeric systems in general and the need for photoresponsive commodity polymers, followed by recent developments of photoresponsive polyolefins with suitable examples. Furthermore, the challenges and future directions of advancing the same are also discussed.
关键词： Photoresponsive,Actuators,Soft-robotics,Polyolefins,Commodity polymers,Stimuli-responsive,Light-responsive
更新于2025-09-23 15:21:01