Optical Fiber Tip wth Integrated Mach-Zehnder Interferometer for Sensor Applications

In this paper, we present design and preparation of novel Mach-Zehnder Interferometer (MZI) based structure for sensing applications. We present integration of this structure at the end of a single-mode optical fiber. Direct laser writing technology was used to prepare MZI-based structure with a hoop for tight connection to optical fiber facet. Details of the design, preparation process and connectorizing process are described and finally, transmission spectral characteristic of the prepared structure was measured using optical spectral analyze

Streamwise-travelling viscous waves in channel flows

The unsteady viscous flow induced by streamwise-travelling waves of spanwise wall velocity in an incompressible laminar channel flow is investigated. Wall waves belonging to this category have found important practical applications, such as microfluidic flow manipulation via electro-osmosis and surface acoustic forcing and reduction of wall friction in turbulent wall-bounded flows. An analytical solution composed of the classical streamwise Poiseuille flow and a spanwise velocity profile described by the parabolic cylinder function is found. The solution depends on the bulk Reynolds number R, the scaled streamwise wavelength (Formula presented.), and the scaled wave phase speed U. Numerical solutions are discussed for various combinations of these parameters. The flow is studied by the boundary-layer theory, thereby revealing the dominant physical balances and quantifying the thickness of the near-wall spanwise flow. The Wentzel–Kramers–Brillouin–Jeffreys (WKBJ) theory is also employed to obtain an analytical solution, which is valid across the whole channel. For positive wave speeds which are smaller than or equal to the maximum streamwise velocity, a turning-point behaviour emerges through the WKBJ analysis. Between the wall and the turning point, the wall-normal viscous effects are balanced solely by the convection driven by the wall forcing, while between the turning point and the centreline, the Poiseuille convection balances the wall-normal diffusion. At the turning point, the Poiseuille convection and the convection from the wall forcing cancel each other out, which leads to a constant viscous stress and to the break down of the WKBJ solution. This flow regime is analysed through a WKBJ composite expansion and the Langer method. The Langer solution is simpler and more accurate than the WKBJ composite solution, while the latter quantifies the thickness of the turning-point region. We also discuss how these waves can be generated via surface acoustic forcing and electro-osmosis and propose their use as microfluidic flow mixing devices. For the electro-osmosis case, the Helmholtz–Smoluchowski velocity at the edge of the Debye–Hückel layer, which drives the bulk electrically neutral flow, is obtained by matched asymptotic expansion

Polymer Based Devices for Photonics on the Chip

In this paper we present promising technology for preparation of photonic devices based on polymer materials on the chip. We designed 2D and 3D structures in CAD (computer-aided design) software and we used two-photon polymerization mechanism for direct writing of these structures to IP-Dip photoresist material. This paper also deals with experimental procedures for preparation of polymer photonic devices on the chip and a new way of light coupling to devices on the chip. Morphological properties of prepared devices were investigated by scanning electron microscope (SEM). As a result, transmission spectrum characteristic was measured

Micro-Optics for Lab-on-a-Chip

Lab-on-a-chip (LOC) is nowadays one of the most interesting topics at the field of biomedicine and biosensing applications. Mainly devices that integrate a detection system right into a chip with microfluidic network are highly desirable. In this article we will present Mach-Zehnder interferometer created in IP-Dip photoresist by direct laser lithography system for laboratory on chip applications. Interferometer will be later used for biosensing application as integrated micro-optical device inside a microfluidic chip. Measurements of transmission characteristics of water solution with different sugar concentration show promising ability of the Mach-Zehnder interferometer to detect different liquids on principle of refractive index change

Interfacing the Control Systems of Enterprise-Level Process Equipment with a Robot Operating System

The analytical section of this paper deals with theoretical knowledge, considering the latest trends in the subject area. To achieve the successful implementation of cobots based on operating systems in manufacturing systems, it is necessary to pay attention specifically to the interfacing of Robot Operating Systems with the control systems of manufacturing systems at the process level of an enterprise. In the practical section, an algorithm with well-defined steps towards the successful implementation of cobots in holonic manufacturing processes is proposed. By setting up an experimental workstation in a laboratory, the proposed procedures are verified at the end of the paper. The creation of a design for the implementation of a collaborative robot with a human represents the missing link in the whole chain of commercial applications of the latest trends from the field of robotic systems in the industrial sphere. The main contributions of this study include the establishment of a communication channel between cobots and programmable logic PLCs (Programmable logic controllers), and an experimental verification of the proposed solution for the implementation of a cooperating robot with a human in a manufacturing system in the laboratory. Another advantage of this paper is the creation of a new procedure for conducting a risk analysis of cooperating robots and multipurpose autonomous devices

Design and simulation of polymer based photonic components

Introducing 3D sub-micrometer technologies based on polymers opened new possibilities of design and fabrication of photonic devices and components in 3D arrangement. 3D laser lithography is direct writing process based on two photon polymerization exhibiting high accuracy and versatility, where numerous resists and even polymer ceramic mixtures can be used. We present design and simulation of polymer based photonic components with a focus on arrayed waveguide gratings (AWG) based on optical multiplexers/demultiplexers and optical splitters. All optical components were designed for 1550 nm operating wavelength, applying two commercial photonics tools. This study creates a basis for the design of optical components in 3D arrangement, which will be fabricated by 3D laser lithography