Konferenzbeiträge

Large Scale Additive Manufacturing (LSAM) based on plastic raw material is known for high material output and thus, increased productivity. For an improvement of part properties LSAM is combined with a laser process. Depending on the deposition direction, the laser beam needs to be repositioned to reach the space between two adjacent and consecutively printed strands. Therefore, an optomechanical design is required that allows variable orientation of the laser beam. It consists of a combination of an elliptical, tube-like mirror with an additional, rotatable flat mirror in one of its focal axes. The deflected laser beam hits the second focal axis where the extruder nozzle is located. Thus, > 75% of the nozzle circumference is covered during a laser beam treatment. Both mirrors are individually designed custom-made parts. Its functional verification lays the foundation for an improved additive manufacturing process, which aims to homogenize the component structures to improve the mechanical properties of 3D-printed components.

The design of a machine frame, supporting a plurality of components/modules, is a major challenge during the development of precision systems. The geometric stability of the supporting parts under thermal and mechanical loads has a decisive influence on the achievable accuracy. Common materials like cast iron or natural stone have preferable properties but often come with high costs and long lead times due to sourcing or manufacturing process and required geometric precision. Concrete is an interesting alternative. Polymer concrete and cement-based concrete such as self-compacting concrete have been considered as cost-effective alternatives for quite a while now. This paper summarizes recent research and findings on these alternative materials and reviews their applicability in machine frame design. Aspects of the cold primary shaping process will be covered with an emphasis on ready-to-use features with geometric tolerances in the order of magnitude of micrometers. The potential for integrating functional elements is discussed. The advantages of concrete as an alternative material are summarized with regard to the application of the design principle "functional material at the location where functionality is required".

The frequent use of a growing diversity of tools in nanofabrication machines raises the need for a highly reproducible tool-changing system that is capable of working with tools of different weights and moments of inertia. Since the tool-changing system is designed beneficially based on an open, force-paired kinematic coupling, means to apply a holding force are required. The holding force needed is about 40 N in total and has to be applied without heat dissipation or other disturbances. Since variations in the elastic deformation at the contact points of the coupling directly influence the reproducibility of the tool position, the force application needs to be highly reproducible. An analytical model is developed to determine the force application requirements, taking into consideration elastic deformation and friction. Based on this model, the allowable variation of the holding force in amount and direction, as well as the allowable deviation of the force application point, are determined. Thereby, the resulting influence of the force application on the reproducibility of the position of the tool-center point is intended to be 5 nm or less. Eleven solution principles for force application are developed based on the physical effects of magnetic force, spring force, and weight force. Based on a systematic evaluation, an arrangement of three permanent magnets with flux guide pieces at an angle of 120˚ to each other has been chosen at the fixed side. On the tool side, ferromagnetic plates are used to close the magnetic circuit. Thereby, the air gap and, thus, the holding force can be adjusted individually for each tool. During the tool change, the magnetic force is switched off by short-circuiting the magnetic flux with an additional rotatory-mounted flux piece, which is driven by a gear motor. The designed prototype will be tested and further optimized within a nanofabrication machine.

This paper is dedicated to the mechanical structure of a force transducer for the measurement of very small forces in the nanonewton range with highest resolution and lowest measurement uncertainty. To achieve this, a low stiffness in one direction of motion, but high stiffness in all other directions of motion is required. Existing solutions that meet the requirements are not suitable because of their overall dimensions. This results in a need for miniaturization. For this purpose, the scaling behavior of an existing monolithic compliant mechanism is investigated and it is verified which joint contour provides an optimal stiffness ratio. It is shown that the corner-filleted contour in general has lower bending stiffnesses, but also lower cross stiffnesses compared to the semi-circular contour. A nonlinear scaling effect for the ratio of bending stiffness and cross stiffness in corner-filleted contour offers optimization potential. Based on a simplified rigid body model, additionally, the miniaturization of the mechanism is optimized. The stiffness in the desired direction of motion is reduced by about 85% compared to a semi-circular contour. The result is promising for the further development of a miniaturized force transducer. The findings of this work contribute to the advancement of the measurement of low forces and offer new perspectives for future research in miniaturized force sensors.

In this research are proposed the consequences of high temperatures in Internal Combustion Motors (ICM) as correlation of its performance according to give information of the ICM fault detector, which also can be useful for preventive maintenance. It was possible to achieve the proposed target because of it was designed a smart sensor based in nanostructures prepared over Anodic Aluminum Oxide (AAO) samples, which proportionated short response time and high robustness in the measurement tasks of the smart sensor, as well as, the designed sensor has the possibility to work by energy self-sufficiency and sending the measurement data to external users by wireless. In fact, it is waited that this research could be a support for researchers of ICM enhancement, who could look for new techniques of environment conditions cares in compensation to keep the balance between the useful energy obtained from ICM and the environment conditions, where are developed economical activities such as public transport or mining in Peru.