Sören Zimmermann

Automated Robotic Manipulation of Individual Colloidal Particles Using Vision-Based Control

Automated manipulation of micro- and nanosized objects using robotic setups constitutes a major challenge due to the force-scaling laws and the limited control possibilities on that scale. This paper presents a new developed approach for automated manipulation of individual colloidal particles using a dedicated dual-probe setup inside a scanning electron microscope. Based on tailored probe geometries, the setup allows for reliable pick-up and release sequences of individual particles. Applying image processing of the visual feedback provided by the microscope enables for direct and fast control of the complex manipulation routines and thus allows for fully automated alignment sequences. Experimental results reveal a high repeatability of the process with hitherto unrivaled precision. The advantages and limits of this technique are highlighted with respect to further application scenarios.

Automated Mechanical Characterization of 2-D Materials using SEM based Visual Servoing

This paper presents an automated handling approach of two-dimensional nanomaterials using a robotic setup inside a high-resolution scanning electron microscope. Applying image processing of the visual feedback provided by the electron microscope, a fully automated sequence is developed to align a robotic driven force sensor with sub micrometer accuracy and to conduct nanoindentation measurements on a periodically perforated substrate. As an example, this automated sequence is utilized to examine the mechanical properties of a few-layer graphene membrane. The results of the mechanical characterization are compared to Raman spectroscopy data. The paper discusses the advantages and restrictions of this technique and responds to further application scenarios.

Robotic dual probe setup for reliable pick and place processing on the nanoscale using haptic devices

This paper presents reproducible pick and place handling of particles within the sub micron range. The handling strategy is based on a robotic dual probe setup that is integrated into a high resolution scanning electron microscope. By purposeful utilization of the predominant adhesive forces on the nanoscale, this setup facilitates the assembly of overall complex arrangements of different nanoparticles using haptic devices. The paper discusses control issues of the setup as well as the advantages and restrictions of the proposed technique.

Nanorobotic Processing of Graphene: A platform tailored for rapid prototyping of graphene-based devices.

Graphene, an ultrathin membrane consisting of carbon, is currently the focus of numerous research groups around the world. Due to its outstanding physical properties, this new type of material is highly promising in enabling several novel applications. However, up until now, the integration of high-quality graphene into real devices remains challenging. This article presents a nanorobotic platform tailored for the rapid prototyping of graphene-based devices. Applying the capabilities of this platform, a nanorobotic strategy is proposed that enables the identification, electrical characterization, and integration of graphene into device structures without using any time-consuming lithographical procedures. In this way, graphene-based devices can be fabricated and classified within a few hours, significantly reducing the effort and, consequently, the costs of device prototyping. As an example of this strategy, graphene flakes are electrically characterized and transferred onto a target area of a final device.

Automated mechanical characterization of 2D materials using SEM based visual servoing

This paper presents an automated handling approach of two-dimensional nanomaterials using a robotic setup inside a high-resolution scanning electron microscope. Applying image processing of the visual feedback provided by the electron microscope, a fully automated sequence is developed to align a robotic driven force sensor with sub micrometer accuracy and to conduct nanoindentation measurements on a periodically perforated substrate. As an example, this automated sequence is utilized to examine the mechanical properties of a few-layer graphene membrane. The results of the mechanical characterization are compared to Raman spectroscopy data. The paper discusses the advantages and restrictions of this technique and responds to further application scenarios.

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.

Nanorobotic handling of few-layer graphene membranes using a combined AFM/SEM/FIB setup

This paper presents a new experimental approach for pick and place handling of few-layer graphene nanomembranes with side length of 10 μm and below. In the as-received condition, the membranes are freely suspended on a grid which is covered with a lacey carbon film. Using focused ion beam cutting and a nanorobotic driven tungsten tip, selected membrane-fragments can be separated from the grid and transferred to any chosen substrate with high accuracy. As an example, one membrane is placed on a hole with a diameter of 5 μm on a Si/SiO2 sample. Subsequently, the membrane is fixed and mechanically characterized. The paper investigates the advantages, the opportunities and the limits of this technique in particular with regard to possible applications.

Nanorobotic transfer and characterization of graphene flakes

This paper presents a nanorobotic approach facilitating the transfer and characterization of individual graphene flakes that are grown by different fabrication techniques. The approach makes use of a nanorobotic atomic force microscope system that is integrated into a high resolution scanning electron microscope and focused ion beam device. This combination is used to perform both, the nanorobotic transfer and the mechanical characterization of the graphene flake allowing to systematically analyze different sample areas and to optimize the fabrication processes. Furthermore, the nanorobotic system enables the reliable pick-and-place handling and processing of graphene flakes to realize more comprehensive analysis steps or even the prototyping of graphene-based devices.

Cubical photonic structures by means of ion beam assisted robotic assembly

Fabrication of tailored photonic structures with sufficient precision is a major topic in photonics since decades. However, until now, the assembly of photonic structures in order to control light propagation in all three spatial dimensions remains challenging. This paper presents a reliable approach for fabricating three-dimensional structures consisting of individually stacked colloidal particles. The combination of a robotic dual-probe setup inside a scanning electron microscope and the purposeful use of ion beam based etching and deposition techniques allows to fabricate on-demand three-dimensional photonic structures with cubic geometry. The advantages and limits of this technique are highlighted with respect to further application scenarios.

Elastic properties of graphene grown by chemical vapor deposition

We measured the elastic properties and breaking strength of free-standing chemical vapor deposition grown graphene membranes by nanoindentation with an atomic force microscope probe in scanning electric microscope. The force-displacement behavior presents to be nonlinear elastic stress-strain response. The two dimension elastic constant and fracture are extracted to be 337 N/m and 179 GPa, respectively. The corresponded effective Youngs modulus is E = 1 TPa, compared to 1 TPa for graphene produced by mechanical exfoliation of graphite and 0.25 TPa for graphene produced by chemical reduction.