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In Part II, we present the use and application of the Compliant Building Elements (CBE) method to generate practical designs for different multiple degree-of-freedom (DOF) compliant mechanisms. We first create a compliant mechanism library based on the combination of prismatic beams, which includes commonly used basic elements (BEs), serial elements (SEs), and parallel elements (PEs). Examples are given during the construction of the library. Based on the library and CBE method, we demonstrate the design of a six-axis nanopositioner, a compliant steering mechanism, and a one-dimensional mechanical metamaterial structure. The outcome of each design process yields a flexure topology that meets the design requirements as well as the corresponding parametric stiffness and compliance matrices, from which we can efficiently obtain the kinematic characteristics of the flexure system and optimize the stiffnesses in selected axes. • CBE is a new design methodology to generate practical designs for multiple degree-of-freedom mechanisms. • CBE combines the advantages of screw theory, matrix-based method, and practical experience to synthesize complex flexures. • A compliant mechanism library is provided based on the combination of prismatic beams to facilitate the design process. • We demonstrate the design process of compliant nanopositioners, steering mechanisms, and metamaterial structures via CBE. [ABSTRACT FROM AUTHOR]

In this paper, we present a new design method and principle, i.e., Compliant Building Elements (CBE), for compliant mechanisms that adopts a systematic and synthetic approach to generate practicable flexure designs. The CBE is unique in that it encodes a compliant system's quantitative information, including elasticity, geometry, location, and orientation, in a parametric matrix. Based on the matrix, a degree-of-freedom (DOF) concept is defined to describe permitted motions of a flexure; next, the screw theory is used to guide the design and synthesis of compliant mechanisms from DOF decomposition to actuator layout selection. In CBE, a compliant system consists of three types of compliant elements, i.e., compliant elements formed by serial or parallel connections and basic compliant elements. The synthesis procedure is a top-down and iterative process, starting from laying out the stage topology to finally optimizing the compliant connection elements and types (i.e., serial or parallel), where the iteration stops when the stage characteristics meet the design requirements. A library of various compliant elements is provided to help the designers quickly generate the initial stage topological designs and optimize the performance with reduced design iterations. The matrix-based design method for compliant mechanisms, i.e., CBE, which is analogous to the screw-based type synthesis for rigid parallel mechanisms, enables early-stage flexure system design via building compliant blocks just like building LEGO® bricks. • Compliant Building Elements (CBE) is a systematic and synthetic design method to generate designs for compliant mechanisms. • In CBE, the synthesis of compliant mechanisms is guided by screw theory and verified by the parametric stiffness/compliance matrices. • The CBE method can be automated to expedite the design process owing to its systematic and matrix operation nature. • The CBE method can benefit inexperienced flexure designers to quickly generate practical design concepts. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the design of a small-scale nanopositioner, the μHexFlex, which is comprised of a six-axis compliant mechanism and three pairs of two-axis thermo-mechanical micro-actuators. In this paper, we cover the modeling, design and fabrication of the μHexFlex. Specific attention is given to: (1) the use of constraint-based design in generating the compliant mechanism design, (2) the modeling of the actuators, and (3) the system model which links the actuator input and mechanism response. The measured, quasi-static performance of a 3mm diameter prototype shows a maximum range of 8.4μm×12.8μm×8.8μm and 19.2mrad×17.5mrad×33.2mrad (1.1°×1.0°×1.9°). Experimental results indicate that a constant mechanical/electrical material property system model may be used to predict the position and orientation over a range of 3.0μm×4.4μm×3.0μm and 6.3mrad×6.3mrad×8.7mrad (0.36°×0.36°×0.5°). The dynamic characteristics of the device were investigated experimentally. Experimental results show a lowest natural frequency of 4kHz. The resolution characteristics of the device have been measured at 1Å/mV. The device was created using deep reactive ion etching (DRIE). Bulk fabrication costs are estimated at less than $ 2 per device. [Copyright &y& Elsevier]

This paper presents a comprehensive review of mechanical design and synthesis methods for piezo-actuated compliant micro-positioning stages, which play an important role in areas where high precision motion is required, including bio-robotics, precision manufacturing, automation, and aerospace. Unlike conventional rigid-link mechanisms, the motion of compliant mechanisms is realized by using flexible elements, whereby deformation requires no lubrication while achieving high movement accuracy without friction. As compliant mechanisms differ significantly from traditional rigid mechanisms, recent research has focused on investigating various technologies and approaches to address challenges in the flexure-based micro-positioning stage in the aspects of synthesis, analysis, material, fabrication, and actuation. In this paper, we reviewed the main concepts and key advances in the mechanical design of compliant piezo-actuated micro-positioning stages, with a particular focus on flexure design, kineto-static modeling, actuators, material selection, and functional mechanisms including amplification and self-guiding ones. We also identified the key issues and directions for the development trends of compliant micro-positioning stages. [ABSTRACT FROM AUTHOR]

With the increasing demand for devices and systems with nanometer precision in the modern manufacturing industry, tip-based nanofabrication (TBN) has become an indispensable part of manufacturing process. However, a common issue that needs to be addressed is to increase the throughput of TBN, which is sequential and inherently slow. To overcome the difficulty, in this paper we present the design and control of a flexure-based five-axis nanopositioner with dynamic-tuning capability for parallel nanomanufacturing applications. The dynamic-tuning method enables trade-offs between the range and speed of the nanopositioner so as to increase the throughput of the nanomanufacturing system. The experimental results indicate that the nanopositioner conforms with the in-plane range and resolution requirements, i.e., ±5 mm/100 nm in X / Y axis, while its natural frequencies in X / Y axis can be increased by two to three times at the expense of decreased stroke, i.e., elastic range. In addition, real-time dynamic-tuning experiments show active vibration cancellation techniques can be implemented on the nanopositioner and effectively eliminate the unwanted dynamics and improve the overall dynamic performance. Lastly, we performed nano-scratching experiments using an 18 tip AFM array to fabricate optical grating patterns on gold coated silicon substrates of 5 × 1 mm 2 to demonstrate the practicality of the new method. The experiment confirmed good parallelism had been achieved during the experiments, where the scratched gold lines have a consistent depth of ∼160 nm. [ABSTRACT FROM AUTHOR]

This paper presents the design, characterization, and control of a flexure-based roll-to-roll (R2R) printing system that achieves nanometer level precision and repeatability. The R2R system includes an unwinding/rewinding module, a web guide mechanism, and a core positioning stage consisting of two monolithic compliant X–Y stages that control the position/force of the print roller. During the printing process, capacitance probes, eddy current sensors and load cells are used to monitor the displacements of the flexure stage and contact force in real time. Control strategies, including decoupling, PID, and cascade control, have been implemented to decouple the cross-axis and cross-stage motion coupling effect and improve the overall precision and dynamic performance. In actual printing processes, the contact force and roller position can be uniformly controlled within ±0.05 N and ±200 nm respectively across a 4 in. wide PET web. To demonstrate the performance, a positive microcontact printing (MCP) process is adapted to the R2R system, printing various fine metal patterns, e.g., optical gratings and electrodes, in a continuous fashion. [ABSTRACT FROM AUTHOR]