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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]

Roll-to-roll (R2R) printing technologies have been widely adopted in a variety of engineering fields, e.g., organic photovoltaics and flexible electronics, owing to the advantages of cost and throughput. Although a minimum feature size of 100 nm has been demonstrated on R2R systems, the layer to layer registration accuracy (i.e., overlay accuracy) still remains as low as tens of microns, which prevents the fabrication of common electronic and functional devices, such as transistors. To realize the full potential of R2R technologies, the registration accuracy must be improved to match the printing resolution, i.e., 100s nm. To address the issue, we have developed a multi-layer R2R system with multiple-input multiple-output (MIMO) closed-loop control that achieves submicron level alignment precision for large-scale continuous printing processes. The enabling elements in the multi-layer R2R system include: (1) new vision-based alignment algorithm/method, which provides 100s nm position detection capability based on low-cost cameras; and (2) custom-built five-axis compliant roller positioner. Experimental results show that the compliant roller positioner has a ±1 mm range with 100s nm precision in X, Y, and Z axes respectively. For correcting in-plane web errors, the roller positioner can achieve a range of 1 mm with < 1 μm precision, realizing multi-layer R2R printing with submicron overlay accuracy. Based on the new methods, a gate/source-drain multi-layer electrode structure for field-effect transistors (FETs) has been designed and fabricated on a 4-inch PET web, demonstrating better than 1 μm overlay precision in fabricating flexible electronics on a R2R platform for the first time. • The first demonstration of a multi-layer R2R printing system that achieves better than 1 μm overlay accuracy. • The five-axis roller positioner actively corrects position errors with a precision of ±200 nm and ±2 μrad. • The new alignment solution achieves a large detection range (> 1 mm) with high-resolution (10s nm) based on low-cost cameras. • R2R printing of a multi-layer structure, i.e., FETs, was demonstrated on a 4-inch PET web with < 1 μm overlay precision. [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]