Claas Diederichs

Combined nanorobotic AFM/SEM system as novel toolbox for automated hybrid analysis and manipulation of nanoscale objects

In this paper, the concept and first results of a novel toolbox for nanoscale characterization are presented. A nanorobotic AFM system is being developed and integrated into a high resolution SEM/FIB system allowing nanoanalysis, -manipulation and -structuring. The compact and modular AFM setup enables probe- as well as sample-scanning and uses self-sensing AFM cantilevers. Image fusion algorithms are developed to merge SEM and AFM information for hybrid analysis of nanoscale objects. A commercial AFM controller is embedded into a special control system architecture that allows for automation of nanomanipulation sequences.

Hardware-Software Co-Design Tracking System for Predictable High-Speed Mobile Microrobot Position Control

Abstract Fast closed-loop control is a key issue for high-throughput automated micro-and nanohandling. Currently, mobile robot position control relies on computer vision using FireWire- or USB-cameras. This approach has several drawbacks for closed-loop control, such as limited update rate, high latency and unpredictable jitter. To overcome these drawbacks, a new hardware-based position tracking algorithm is presented and compared to current position control sensors. Additionally, several measurements of a closed-loop controlled mobile robot for micro- and nanohandling show the systems advanced performance in terms of speed and accuracy using the new sensor.

Automated robotic assembly for a micro-cartridge system inside the scanning electron microscope.

The AFM is a common tool for ultra-precise surface characterization and a standard instrument a variety of research and development disciplines. However, the characterization of three dimensional high-aspect ratio and sidewall structures remains a hardly accomplishable task. Novel exchangeable and customizable scanning probe tips - NanoBits - can be attached to standard AFM cantilevers offering unprecedented freedom in adapting the shape and size of the tips. These NanoBits of few μm size have to be assembled into micro-cartridges. This challenging assembly task is performed inside the SEM by a micro-gripper. A powerful automation framework has been developed facilitating image based automation and visual servoing for this task. Template matching, BLOB-detection, and special SEM-based detection approaches are used to achieve the automated assembly.

Integrating robotic software frameworks for convenient software component exchange in micro- and nanoscale applications

Software development is a little discussed but essential part of micro- and nanoscale robotic systems. Current robotic systems are often controlled by a monolithic software that is either provided by the hardware manufacturer or specially tailored software for a particular application. One of the major challenges is to provide the research community with means that enable easy integration of software produced by different partners. The provided solution should not be bound to any particular programming language or scheme. This paper describes the currently used software approaches in control of micro- and nanorobotic systems. Progress towards convenient software integration is showcased by integrating two robotic software frameworks OFFIS automation framework and ROS. The first is an example of micro- and nanoscale oriented robotic software frameworks and the latter is designed for the needs of conventional robotic applications. The proposed integration approach is validated by an exemplary use case of a pick-and-place operation.

Towards automated AFM-based nanomanipulation in a combined nanorobotic AFM/HRSEM/FIB system

In this paper, the semi-automated AFM-based nanomanipulation of silica spheres with a radius of 550 nm is presented. A combined AFM/HRSEM/FIB system is used to facilitate the SEM vision-based pick-and-place handling with haptic feedback. Object recognition and tracking algorithms are described supporting the automated localization of micro-and nanospheres. Automated alignment of source and target sample positions is realized to support fast exchange of different substrates and to speed up the pick-and-place procedure. The integration of a haptic feedback device allows for intuitive AFM-based nanomanipulation with force feedback. The silica spheres are assembled into 2×2 μm arrays for applications in infrared spectroscopy.

FPGA-Based Object Detection and Motion Tracking in Micro- and Nanorobotics

Object-detection and classification is a key task in microand nanohandling. The microscopic imaging is often the only available sensing technique to detect information about the positions and orientations of objects. FPGA-based image processing is superior to state of the art PC-based image processing in terms of achievable update rate, latency and jitter. A connected component labeling algorithm is presented and analyzed for its high speed object detection and classification feasibility. The features of connected components are discussed and analyzed for their feasibility with a single-pass connected component labeling approach, focused on principal component analysis-based features. It is shown that an FPGA implementation of the algorithm can be used for high-speed tool tracking as well as object classification inside optical microscopes. Furthermore, it is shown that an FPGA implementation of the algorithm can be used to detect and classify carbon-nanotubes (CNTs) during image acquisition in a scanning electron microscope, allowing fast object detection before the whole image is captured. FPGA-Based Object Detection and Motion Tracking in Microand Nanorobotics

Tracking algorithms for closed-loop positioning of mobile microrobots

Visual servoing of tools and object detection are major tasks of serial micro-assembly, as the visual feedback is often the only way to track positions. High speed cameras can be used for high speed automated micromanipulation. This paper analyzes different object tracking approaches for their feasibility of high speed tracking. First, state of the art software algorithms are analyzed. Second, a hardware approach is analyzed. All algorithms are compared in terms of high-speed feasibility, movement speed and limitations. The comparison shows that hardware-based approaches are needed for update frequencies beyond 100 Hz.

Fast Visual Servoing of Multiple Microrobots Using an FPGA-Based Smart Camera System

Abstract In microrobotics, visual servoing is often the only way to track the position of a robot or manipulator. To allow for automated high-speed micromanipulation, reliable highspeed visual servoing systems are needed. This paper presents a smart camera implementation that is capable of tracking multiple microrobots with an accuracy below 2 μm inside a working range of 120 × 80 mm 2 using a state of the art CMOS vision sensor. The implementation of the tracking algorithm was partly carried out in hardware to allow for predictable signal latency and high update rate. The system is capable of tracking a single robot with an update rate of over 200 Hz.

Closing the loop: High-speed visual servoing and control of a commercial nanostage inside the SEM

In micro- and nanorobotics, it is important to increase closed-loop performance to achieve high-throughput for industrial applications. By using dedicated line scans instead of scanning microscope image acquisition, bottlenecks such as limited update rate, long latency and unpredictable jitter can be overcome. Earlier experiments used the line-scan approach for visual servoing of a custom made mobile robot. In this paper, the line-scan approach is used to guide the closed loop positioning of a Physik Instrumente (PI) nanostage. Additionally to the linescan controller and the commercial PI-stage controller, an FPGA system that acts as additional position controller was developed. Several evaluation measurements show the performance of the implementation in terms of accuracy and performance for the nanorobotic stage.

Hardware-based, Trajectory-Controlled Visual Servoing of Mobile Microrobots

Abstract Visual servoing based on camera or microscopic feedback has become a widely acknowledged technique for the positioning of robots. With a hardware-based image processing and tracking architecture, classic timing downsides such as low update rates, latency and jitter can be bypassed making visual servoing efficient. Applying this tracking to mobile nanohandling robots, a compact high-performance micro- and nanopositioning system is realized. Trajectory control becomes feasible due to the deterministic timing behavior of the position tracking as well as the reliable open-loop control of the robots. Measurement results demonstrate the excellent characteristics of the CMOS camera-based tracking system, the mobile nanohandling robots and the trajectory-controlled positioning. Although initially aimed at coarse positioning, the system achieves accuracies below 1 ±m.