Showing papers on "Bimorph published in 2015"

A Graphene-Based Bimorph Structure for Design of High Performance Photoactuators

Abstract: A photoactuator based on a tubular-shaped graphene composite bimorph is fabricated and shows reversible photoactuation with fast response and large deformation (deformation angle of ca. 479° in only 3.6 s), which is mostly attributed to the interfacial thermal stress. Various photoactuator devices based on the tubular bimorph, including a smart box and crawler-type robot that can mimic tank-track motion, are designed.

Unified nonlinear electroelastic dynamics of a bimorph piezoelectric cantilever for energy harvesting, sensing, and actuation

Abstract: Inherent nonlinearities of piezoelectric materials are pronounced in various engineering applications such as sensing, actuation, combined applications for vibration control, and energy harvesting from dynamical systems The existing literature focusing on the dynamics of electroelastic structures made of piezoelectric materials has explored such nonlinearities separately for the problems of mechanical and electrical excitation Similar manifestations of softening nonlinearities have been attributed to purely elastic nonlinear terms, coupling nonlinearities, hysteresis alone, or a combination of these effects by various authors In order to develop a unified nonlinear nonconservative framework with two-way coupling, the present work investigates the nonlinear dynamic behavior of a bimorph piezoelectric cantilever under low to moderately high mechanical and electrical excitation levels in energy harvesting, sensing, and actuation The highest voltage levels, for near resonance investigation, are well below the coercive field A distributed parameter electroelastic model is developed by accounting for softening and dissipative nonlinearities to analyze the primary resonance of a soft (eg, PZT-5A, PZT-5H) piezoelectric cantilever for the fundamental bending mode using the method of harmonic balance Excellent agreement between the model and experimental investigation is found, providing evidence that quadratic stiffness, damping, and electromechanical coupling effects accurately model predominantly observed nonlinear effects in geometrically linear vibration of piezoelectric cantilever beams The backbone curves of both energy harvesting and actuation frequency responses for a PZT-5A cantilever are experimentally found to be dominantly of first order and specifically governed by ferroelastic quadratic softening for a broad range of mechanical and electrical excitation levels Cubic and higher-order nonlinearities become effective only near the physical limits of the brittle and stiff (geometrically linear) bimorph cantilever when excited near resonance

Modeling and analysis of Lamb wave propagation in a beam under lead zirconate titanate actuation and sensing

Abstract: Lead zirconate titanate actuators and sensors have been the widely used in Lamb wave–based damage detection applications. The excitation frequency, waveform, and wave propagation characteristics should be comprehensively considered to effectively conduct diagnosis of incipient forms of damage. In this article, we investigate Lamb wave propagation in a beam under lead zirconate titanate actuation/sensing, in which the lead zirconate titanate effects are included. First, mathematical models are developed to account for both unimorph (i.e. sensor mode) and bimorph (i.e. actuator mode) configurations. The Timoshenko beam theory is adopted for both base beam and lead zirconate titanate layers to accommodate high-frequency responses. Second, the fully coupled electromechanical governing equations are determined and solved in an analytical form to formulate the spectral finite element model. Finally, parametric studies are carried out to determine the optimal actuation frequency, sensor size, actuator, and senso...

Reconfiguring photonic metamaterials with currents and magnetic fields

Abstract: We demonstrate that spatial arrangement and optical properties of metamaterial nanostructures can be controlled dynamically using currents and magnetic fields. Mechanical deformation of metamaterial arrays is driven by both resistive heating of bimorph nanostructures and the Lorentz force that acts on charges moving in a magnetic field. With electrically controlled transmission changes of up to 50% at sub-mW power levels, our approaches offer high contrast solutions for dynamic control of metamaterial functionalities in optoelectronic devices.

Constructive and Destructive Interplay Between Piezoelectricity and Flexoelectricity in Flexural Sensors and Actuators

Abstract: Flexoelectricity is an electromechanical effect coupling polarization to strain gradients. It fundamentally differs from piezoelectricity because of its size-dependence and symmetry. Flexoelectricity is generally perceived as a small effect noticeable only at the nanoscale. Since ferroelectric ceramics have a particularly high flexoelectric coefficient, however, it may play a significant role as piezoelectric transducers shrink to the submicrometer scale. We examine this issue with a continuum model self-consistently treating piezo- and flexoelectricity. We show that in piezoelectric device configurations that induce strain gradients and at small but technologically relevant scales, the electromechanical coupling may be dominated by flexoelectricity. More importantly, depending on the device design flexoelectricity may enhance or reduce the effective piezoelectric effect. Focusing on bimorph configurations, we show that configurations that are equivalent at large scales exhibit dramatically different behavior for thicknesses below 100 nm for typical piezoelectric materials. Our results suggest flexoelectric-aware designs for small-scale piezoelectric bimorph transducers.

Piezoelectric Energy Harvesting in Internal Fluid Flow

Abstract: We consider piezoelectric flow energy harvesting in an internal flow environment with the ultimate goal powering systems such as sensors in deep oil well applications. Fluid motion is coupled to structural vibration via a cantilever beam placed in a converging-diverging flow channel. Two designs were considered for the electromechanical coupling: first; the cantilever itself is a piezoelectric bimorph; second; the cantilever is mounted on a pair of flextensional actuators. We experimentally investigated varying the geometry of the flow passage and the flow rate. Experimental results revealed that the power generated from both designs was similar; producing as much as 20 mW at a flow rate of 20 L/min. The bimorph designs were prone to failure at the extremes of flow rates tested. Finite element analysis (FEA) showed fatigue failure was imminent due to stress concentrations near the bimorph’s clamped region; and that robustness could be improved with a stepped-joint mounting design. A similar FEA model showed the flextensional-based harvester had a resonant frequency of around 375 Hz and an electromechanical coupling of 0.23 between the cantilever and flextensional actuators in a vacuum. These values; along with the power levels demonstrated; are significant steps toward building a system design that can eventually deliver power in the Watts range to devices down within a well.

Improvements in energy harvesting capabilities by using different shapes of piezoelectric bimorphs

Abstract: The small amount of power needed by microelectronic devices opens up the possibility to convert part of the vibration energy present in the environment into electrical energy, using several methods. One such method is to use piezoelectric material as an additional layer in cantilever beams to harvest vibration energy for self-powered sensors. The geometry of a piezoelectric cantilever beam will greatly affect its vibration energy harvesting ability. Tapering and changing the configuration as ways to increase the generated output power of cantilever piezoelectric energy harvesters have gained popularity in recent years. In this work vibration energy harvesting via piezoelectric resonant bimorph cantilevers is studied and new designs for obtaining optimal piezoelectric energy harvesters are suggested. This paper deduces a very precise and simple analytical formula that can be used as a rule of thumb for calculating the resonant frequency of bimorph trapezoidal V-shaped cantilevers using the Rayleigh–Ritz method. This analytical formula is then analyzed using MATLAB as well as finite element methods and validated by ABAQUS simulation. Also, mathematical derivations for the output voltage of bimorph piezoelectric energy harvesters are presented and validated by simulation and experimental results. These formulas provide a new perspective that, among all the bimorph trapezoidal V-shaped cantilever beams with uniform thickness, the bimorph triangular tapered cantilever can lead to the highest resonant frequency and therefore maximum sensitivity, and by increasing the ratio of the trapezoidal bases the sensitivity decreases. Also, the output voltage and strain distribution show that the triangular cantilever has the highest efficiency and power density.

A Fast, Large-Stroke Electrothermal MEMS Mirror Based on Cu/W Bimorph

Abstract: This paper reports a large-range electrothermal bimorph microelectromechanical systems (MEMS) mirror with fast thermal response. The actuator of the MEMS mirror is made of three segments of Cu/W bimorphs for lateral shift cancelation and two segments of multimorph beams for obtaining large vertical displacement from the angular motion of the bimorphs. The W layer is also used as the embedded heater. The silicon underneath the entire actuator is completely removed using a unique backside deep-reactive-ion-etching DRIE release process, leading to improved thermal response speed and front-side mirror surface protection. This MEMS mirror can perform both piston and tip-tilt motion. The mirror generates large pure vertical displacement up to 320 μm at only 3 V with a power consumption of 56 mW for each actuator. The maximum optical scan angle achieved is ±18° at 3 V. The measured thermal response time is 15.4 ms and the mechanical resonances of piston and tip-tilt modes are 550 Hz and 832 Hz, respectively.

A versatile multi-user polyimide surface micromachinning process for MEMS applications

Abstract: This paper reports a versatile multi-user micro-fabrication process for MEMS devices, the “Polyimide MEMS Multi-User Process” (PiMMPs). The reported process uses polyimide as the structural material and three separate metallization layers that can be interconnected depending on the desired application. This process enables for the first time the development of out-of-plane compliant mechanisms that can be designed using six different physical principles for actuation and sensing on a wafer from a single fabrication run. These principles are electrostatic motion, thermal bimorph actuation, capacitive sensing, magnetic sensing, thermocouple-based sensing and radio frequency transmission and reception.

Bimorph pMUT with dual electrodes

Abstract: The concept of “bimorph” piezoelectric micromachined ultrasonic transducers (pMUTs) has been demonstrated by utilizing a two active AlN layers structure constructed in a CMOS-compatible process. The prototype device has two 0.95µm-thick AlN layers sandwiched by three 0.15µm-thick Mo electrodes. In a prototype, both an inner circular and an outer annular electrode are designed on a 230 µm in radius, circular-shape diaphragm. When actuated with the inner electrode of 160µm in radius, the pMUT has a resonant frequency of 198.8 kHz and central displacement of 407.4 nm/V. Under the differential drive scheme using the dual-electrodes for large acoustic outputs at a low frequency, the measured central displacement is 13.0 nm/V, which is about 400% higher than that of a unimorph AlN-pMUT under similar actuation conditions. As such, the dual-electrode bimorph pMUT presents the improved operation as compared with the state-of-the-art flat pMUT design to achieve enhanced acoustic outputs.

Characterization of a next-generation piezo bimorph X-ray mirror for synchrotron beamlines

Abstract: Piezo bimorph mirrors are versatile active optics used on many synchrotron beamlines. However, many bimorphs suffer from the `junction effect': a periodic deformation of the optical surface which causes major aberrations to the reflected X-ray beam. This effect is linked to the construction of such mirrors, where piezo ceramics are glued directly below the thin optical substrate. In order to address this problem, a next-generation bimorph with piezos bonded to the side faces of a monolithic substrate was developed at Thales-SESO and optimized at Diamond Light Source. Using metrology feedback from the Diamond-NOM, the optical slope error was reduced to ∼0.5 µrad r.m.s. for a range of ellipses. To maximize usability, a novel holder was built to accommodate the substrate in any orientation. When replacing a first-generation bimorph on a synchrotron beamline, the new mirror significantly improved the size and shape of the reflected X-ray beam. Most importantly, there was no evidence of the junction effect even after eight months of continuous beamline usage. It is hoped that this new design will reinvigorate the use of active bimorph optics at synchrotron and free-electron laser facilities to manipulate and correct X-ray wavefronts.

Advanced in situ metrology for x-ray beam shaping with super precision

Abstract: We report a novel method for in situ metrology of an X-ray bimorph mirror by using the speckle scanning technique. Both the focusing beam and the “tophat” defocussed beam have been generated by optimizing the bimorph mirror in a single iteration. Importantly, we have demonstrated that the angular sensitivity for measuring the slope error of an optical surface can reach accuracy in the range of two nanoradians. When compared with conventional ex-situ metrology techniques, the method enables a substantial increase of around two orders of magnitude in the angular sensitivity and opens the way to a previously inaccessible region of slope error measurement. Such a super precision metrology technique will be beneficial for both the manufacture of polished mirrors and the optimization of beam shaping.

Fabrication of multilayer Pb(Zr,Ti)O3thin film by sputtering deposition for MEMS actuator applications

Abstract: Multimorph structures composed of multiple thin-film piezoelectric layers and electrode layers were realized by sputtering deposition. Cantilevers with four layers of Pb(Zr,Ti)O3 (PZT) thin film are fabricated and evaluated. The electrical and piezoelectric characteristics of each PZT layer are very similar and are comparable to those of conventional single-layer PZT thin film. The piezoelectric constant d31 is estimated to be −38.3 pm/V from the relationship between tip displacement and applied voltage under the condition of driving four all piezoelectric layers. The generative force is also estimated from the tip displacement. It is confirmed that multimorph cantilevers have larger generative force than those of conventional unimorph and bimorph cantilevers for identical driving voltage.

An Exact Analytical Solution to Exponentially Tapered Piezoelectric Energy Harvester

Abstract: It has been proven that tapering the piezoelectric beam through its length optimizes the power extracted from vibration based energy harvesting. This phenomenon has been investigated by some researchers using semianalytical, finite element and experimental methods. In this paper, an exact analytical solution is presented to calculate the power generated from vibration of exponentially tapered unimorph and bimorph with series and parallel connections. The mass normalized mode shapes of the exponentially tapered piezoelectric beam with tip mass are implemented to transfer the proposed electromechanical coupled equations into modal coordinates. The steady states harmonic solution results are verified both numerically and experimentally. Results show that there exist values for tapering parameter and electric resistance in a way that the output power per mass of the energy harvester will be maximized. Moreover it is concluded that the electric resistance must be higher than a specified value for gaining more power by tapering the beam.

Extremely high-power CO2 laser beam correction.

Abstract: This paper presents the design of the closed loop adaptive system to measure and correct for the aberrations of CO2 laser radiation. We considered two wavefront sensors—one sensor is based on commercially available IR camera while the second one—on the so-called thin film sensors. Also we present the design of two bimorph deformable mirrors to be used under high power laser radiation. We discuss both positive and negative attributes of these devices and the possibility to use them in the real laser high-power systems.

A new electrical configuration for improving the range of piezoelectric bimorph benders

Abstract: This article describes a new electrical configuration for driving piezoelectric benders. The ‘Biased Bipolar’ configuration is compatible with parallel-polled, bimorph and multimorph benders. The new configuration is similar to the standard three-wire drive method where the top electrode is biased with a DC voltage and the bottom electrode is grounded. However, the new configuration uses an alternate DC bias voltage and adjusted range for the central electrode which allows the full range of positive and negative electric fields to be utilized. Using this technique, the predicted deflection and force can be increased by a factor of 2.2 compared to the standard two wire configuration and 1.3 times for the standard three wire configuration. These predictions were verified experimentally where the measured factor of improvement in displacement and force was of 2.4 and 1.3 compared to the standard two-wire and three-wire configurations.

Nonlinear dynamics of piezoelectric nanocomposite energy harvesters under parametric resonance

Abstract: This paper deals with geometrically nonlinear analysis of piezoelectric nanocomposite energy harvesters under principle parametric resonance in prebuckling and postbuckling domains. This vibration-to-electricity conversion system consists of a bimorph piezoelectric beam under simply supported boundary conditions. The electromechanically coupled governing equations of piezoelectric composite beam are obtained based on Euler–Bernoulli beam theory and von Karman geometric nonlinearity. The material properties of nanocomposite beam are assumed to be graded in the thickness direction. The single-walled carbon nanotubes are assumed aligned, straight and a uniform layout. The Galerkin’s method is employed to derive the nonlinear coupled governing equations of the problem which are then solved by using the perturbation scheme of Poincare–Lindstedt. In the numerical examples, the critical buckling load, natural frequency, postbuckling path, output voltage and the harvested power near the first principal parametric resonance under different carbon nanotube distribution pattern and volume fraction are analyzed. Numerical results showed that in the buckled configuration, the device exhibits superior power generation even within a small deviation from the critical buckling state, compared to the unbuckled state. The results also confirm that a functionally graded reinforcement has a significant influence on the bifurcation buckling, postbuckling path, natural frequencies, output voltage and harvested power of the nanocomposite beams.

Fabrication and Characterization of Nitinol-Copper Shape Memory Alloy Bimorph Actuators

Abstract: This study aims to examine the effect of annealing conditions on nitinol (NiTi) characteristics and applies this knowledge to fabricate a NiTi-copper shape memory alloy bimorph actuator. The effect of the annealing conditions was investigated at various temperatures, i.e., 500, 600, and 650 °C, for 30 min. With the characterizations using x-ray diffraction, energy dispersive spectroscopy, and differential scanning calorimetry techniques, the results showed that annealing temperatures at 600 and 650 °C were able to appropriately form the crystalline structure of NiTi. However, at these high annealing temperatures, the oxide on a surface was unavoidable. In the fabrication of actuator, the annealing at 650 °C for 30 min was chosen, and it was performed at two pre-stressing conditions, i.e., straight and curved molds. From static and dynamic response experiments, the results suggested that the annealing temperature significantly affected the deflection of the actuator. On the other hand, the effect of pre-stressing conditions was relatively small. Furthermore, the micro gripper consisting of two NiTi-copper bimorph actuators successfully demonstrated for the viability of small object manipulation as the gripper was able to grasp and hold a small plastic ball with its weight of around 0.5 mg.

Wavelength-selective and rebound-able bimorph photoactuator driven by a dynamic mass transport process

Abstract: We fabricated wavelength-selective bimorph film photoactuators based on selective light absorption of Au nanocrystals. The dynamic mass transport of water in a chitosan layer leads to ultra-high sensitivity to temperature and a unique post-irradiation rebound behaviour. This work may provide a new design strategy for producing photoactuators with improved performance.

Thin-film piezoelectric bimorph actuators with increased thickness using double Pb[Zr,Ti]O3 layers

Abstract: We studied the effects of increasing the thickness of bimorph structures containing double layers of Pb(Zr,Ti)O3 (PZT) thin films. Thick PZT films allow high-voltage application (e.g. in terms of coercive electric field and breakdown voltage) and large generative force, which are effective in microelectromechanical systems (MEMS) applications. Improvement of the deposition conditions and electrode structures facilitates the fabrication of the thin-film PZT/PZT bimorph structure. The PZT/PZT bimorph with a total thickness of 5.8 µm, deposited using a radio-frequency (RF) magnetron sputtering system is much thicker than conventional bimorph structures. The characteristics of the two piezoelectric layers were similar to each other and revealed good electric and ferroelectric characteristics with a remanent polarization of 20 µC cm−2 and a coercive electric field of 50 kV cm−1. PZT/PZT bimorph cantilevers were fabricated in order to evaluate their characteristics for actuator applications. The residual stress of the bimorph cantilever was reduced by an annealing process. The vibration test on the fabricated bimorph cantilevers during electrical voltage application revealed a twice as large displacement as compared with a single layer actuation, and the piezoelectric coefficient value d31 was estimated to be −61 pm V−1, which is better than the value of conventional PZT/PZT bimorph cantilevers (−13 pm V−1). It was also shown that the influence of the temperature change is much less than that in unimorph structures with similar dimensions. The evaluated results demonstrate that the PZT/PZT bimorph structures are effective as MEMS devices.

A forefinger-like tactile sensor for elasticity sensing based on piezoelectric cantilevers

Abstract: Current researches on tactile sensors are mainly focused on force sensing, but studies on elasticity sensing are very lacking. In this work, a forefinger-like tactile sensor is proposed with the functions of force sensing, contact prediction, and elasticity sensing. The sensor is made of a piezoelectric bimorph cantilever with a strain gauge for deformation monitoring. A cone-shaped tip is fabricated on the cantilever’s free end to contact the testing sample. When the sensor approaches to the sample’s surface, the bimorph cantilever is excited to vibrate in its flexure mode. Consequently, the vibration amplitude would shift regularly when the tip is close enough to the sample, leading to the contact prediction function. When the tip touches the sample, the sample’s elasticity can be derived by tracking the contact resonance frequency of the cantilever-sample system. The functions of the proposed sensor were carefully examined and excellent performances were achieved. The proposed sensor is adaptive and may hold potentials in sample characterization in industry.

Self-sensing control of piezoelectric positioning stage by detecting permittivity

Abstract: Piezoelectric displacement contains hysteresis and creep properties. Therefore, a displacement sensor is indispensable in precise positioning devices; however, the additional space and cost are problems. On the other hand, self-sensing methods that utilize the piezoelectric actuator itself as the displacement sensor have been proposed. With these self-sensing methods, precise positioning becomes possible without an additional displacement sensor. We developed a self-sensing method utilizing the non-hysteresis relationship between the permittivity change and the piezoelectric displacement. Furthermore, a differential current measurement method using two piezoelectric elements with a bimorph actuator could improve the positioning accuracy. In this study, we examine the control of a positioning stage using two multilayered piezoelectric actuators by applying the differential current measurement method for self-sensing control. The results indicate that the differential current measurement method is effective for precise positioning control. The positioning errors due to hysteresis decreased from 0.8 μm to 0.1 μm for a 10 μm displacement range. In addition, permittivity feedback control could compensate for the creep property.

Two-dimensional in situ metrology of X-ray mirrors using the speckle scanning technique

Abstract: In situ metrology overcomes many of the limitations of existing metrology techniques and is capable of exceeding the performance of present-day optics. A novel technique for precisely characterizing an X-ray bimorph mirror and deducing its two-dimensional (2D) slope error map is presented. This technique has also been used to perform fast optimization of a bimorph mirror using the derived 2D piezo response functions. The measured focused beam size was significantly reduced after the optimization, and the slope error map was then verified by using geometrical optics to simulate the focused beam profile. This proposed technique is expected to be valuable for in situ metrology of X-ray mirrors at synchrotron radiation facilities and in astronomical telescopes.

Hydrodynamic thrust generation and power consumption investigations for piezoelectric fins with different aspect ratios

Abstract: Bio-inspired hydrodynamic thrust generation using piezoelectric transduction has recently been explored using Macro-Fiber Composite (MFC) actuators. The MFC technology strikes a balance between the actuation force and structural deformation levels for effective swimming performance, and additionally offers geometric scalability, silent operation, and ease of fabrication. Recently we have shown that mean thrust levels comparable to biological fish of similar size can be achieved using MFC fins. The present work investigates the effect of length-to-width (L/b) aspect ratio on the hydrodynamic thrust generation performance of MFC cantilever fins by accounting for the power consumption level. It is known that the hydrodynamic inertia and drag coefficients are controlled by the aspect ratio especially for L/b< 5. The three MFC bimorph fins explored in this work have the aspect ratios of 2.1, 3.9, and 5.4. A nonlinear electrohydroelastic model is employed to extract the inertia and drag coefficients from the vibration response to harmonic actuation for the first bending mode. Experiments are then conducted for various actuation voltage levels to quantify the mean thrust resultant and power consumption levels for different aspect ratios. Variation of the thrust coefficient of the MFC bimorph fins with changing aspect ratio is also semi-empirically modeled and presented.

Adaptive optics vision simulation and perceptual learning system based on a 35-element bimorph deformable mirror

Abstract: An adaptive optics visual simulation combined with a perceptual learning (PL) system based on a 35-element bimorph deformable mirror (DM) was established. The larger stroke and smaller size of the bimorph DM made the system have larger aberration correction or superposition ability and be more compact. By simply modifying the control matrix or the reference matrix, select correction or superposition of aberrations was realized in real time similar to a conventional adaptive optics closed-loop correction. PL function was first integrated in addition to conventional adaptive optics visual simulation. PL training undertaken with high-order aberrations correction obviously improved the visual function of adult anisometropic amblyopia. The preliminary application of high-order aberrations correction with PL training on amblyopia treatment was being validated with a large scale population, which might have great potential in amblyopia treatment and visual performance maintenance.

Piezoelectric Energy Harvesting Using PZT Bimorphs and Multilayered Stacks

Abstract: Piezoelectric materials have a unique ability to interchange electrical and mechanical energy. This property allows the absorption of mechanical energy such as ambient vibration and its transformation into electrical energy. The electrical energy generated can be used to power low-power electronic devices. In the present study, energy harvesting by lead zirconate titanate (PZT) multilayer (ML) stacks and bimorphs is presented. The devices were fabricated by a tape casting technique and were poled at 2 kV/mm for 30 min immersed in a silicone oil bath maintained at 60°C. The energy harvesting characteristics of the fabricated devices were measured in a suitably assembled test setup. The output voltage obtained from the PZT bimorphs and ML stacks was 450 mV and 125 mV, respectively. The higher output voltage from the bimorph is due to its low capacitance.

Electrothermally-Actuated Micromirrors with Bimorph Actuators--Bending-Type and Torsion-Type.

Abstract: Three different electrothermally-actuated MEMS micromirrors with Cr/Au-Si bimorph actuators are proposed. The devices are fabricated with the SOIMUMPs process developed by MEMSCAP, Inc. (Durham, NC, USA). A silicon-on-insulator MEMS process has been employed for the fabrication of these micromirrors. Electrothermal actuation has achieved a large angular movement in the micromirrors. Application of an external electric current 0.04 A to the bending-type, restricted-torsion-type, and free-torsion-type mirrors achieved rotation angles of 1.69°, 3.28°, and 3.64°, respectively.

Investigating potential substrates to maximize out-of-plane deflection of piezoelectric macro-fiber composite actuators

Abstract: The work summarized here explores the application of various substrate materials to macro-fiber composites for the purpose of generating curvature. This research experimentally determines the free strain of the macro-fiber composite through its full range of actuation and then examines the resulting deflections when bonded to various substrates. In addition, loads are applied to the resulting unimorph while in a cantilever configuration and the deflections recorded. These results are used to validate finite element models, which are used to explore further design possibilities, including a bimorph configuration. The goal of this work is to determine the substrates that maximize curvature in both unloaded and loaded configurations. The results show that using thin and high modulus substrates results in the largest deflection under loading.