Article
Optics
Simone Sorgato, Lien Smeesters, Michael Vervaeke, Kurt Rochlitz, Dries Rosseel, Jef Verbaenen, Hugo Thienpont, Thomas Geernaert, Jurgen Van Erps
Summary: This study presents the development of a compact optical lightguide for sensing applications, utilizing a unique design and molding technique to achieve desired optical functionalities and mechanical properties. The first prototypes have been fabricated and will soon undergo validation testing.
Article
Optics
David H. Lippman, Greg R. Schmidt, Julie L. Bentley, Duncan T. Moore, Hooman Akhavan, John Paul Harmon, George M. Williams
Summary: In this work, gradient-index Alvarez lenses (GALs), a new type of freeform optical component, are surveyed for their unique properties in generating variable optical power. GALs display behavior similar to conventional surface Alvarez lenses (SALs) through a recently achievable refractive index distribution in fabrication. The authors present a first-order framework for GALs, including analytical expressions for their refractive index distribution and power variation. The study demonstrates the importance of three-dimensional higher-order refractive index terms in the optimized design of GALs. Additionally, a fabricated GAL is showcased, with power measurements closely aligning with the developed first-order theory.
Article
Optics
Jiapu Yan, Zhichao Ye, Tingting Jiang, Shiqi Chen, Huajun Feng, Zhihai Xu, Qi Li, Yueting Chen
Summary: We propose a field of view attention image restoration model for continuous zooming, which simulates degraded images by optimizing the polynomial of Alvarez lenses and achieves better restoration results compared to other methods.
Article
Optics
Jiapu Yan, Zhichao Ye, Tingting Jiang, Shiqi Chen, Huajun Feng, Zhihai Xu, Qi Li, Yueting Chen
Summary: In this study, we proposed a field of view attention image restoration model for continuous zooming to address the optical aberrations of Alvarez lenses. By simulating degraded images and conducting restoration experiments, we demonstrated that our method outperforms compared methods in restoring degraded images across various zoom configurations, while also exhibiting strong generalization capabilities under untrained configurations.
Article
Polymer Science
Qian Ding, Mengxue Du, Tao Liao, Yongfeng Men, Rene Androsch
Summary: The formation and distribution of different crystal forms in ultrasonic microinjection-molded poly(butylene 2,6-naphthalate) (PBN) samples prepared using different mold temperatures were investigated. The results showed that the mold temperature affects the formation of liquid-crystalline (LC) mesophase and alpha-crystals, but not beta'-crystals. LC mesophase and alpha-phase were detected in both skin and core regions, while beta'-crystals were only observed in the skin layer. Different melting temperatures were observed for the crystals in the core region and skin layer, consistent with the different thermal stabilities of alpha- and beta'-phases. The formation of beta'-phase can be achieved under high shear flow, suggesting the polymorphic structure of injection-molded PBN parts can be tailored by varying the molding conditions.
Article
Optics
Leonhard Lenk, Stefan Sinzinger
Summary: Focus-tunable lenses are widely used in optical systems, but correcting chromatic aberrations is still challenging. A combination of lenses and correctors can compensate for chromatic aberrations over a large refractive power range without significantly increasing the system's length.
OPTICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Zhongguo Zhao, Shengtai Zhou, Andrew N. Hrymak, Musa R. Kamal, Taotao Ai
Summary: The study found that the change in injection molding speeds has a significant impact on the crystal structure and formation of beta-nucleated iPP/PET microparts. Increasing injection speeds greatly increases the content of beta-crystals, but reduces the orientation degree of crystal lattice.
POLYMER ENGINEERING AND SCIENCE
(2021)
Article
Optics
Fanqi Shen, Lin Yang, Jun She, Xianliang Zheng, Haifeng Li, Rengmao Wu, Youri Meuret
Summary: This article proposes a method to reshape the beam shape of edge-emitting laser diodes (EELs) using freeform lenses, aiming to overcome the challenge of the strongly asymmetric beam profile. By generalizing the Monge-Ampere method, freeform beam-shaping lenses are designed to achieve flexible and precise control over the luminous distribution of EELs. Three typical and challenging beam-shaping tasks demonstrate that a single compact freeform lens can reshape both the intensity and wavefront of an EEL beam in a desired manner, without any symmetric restrictions on the architecture of the beam-shaping system.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Optics
Mor Elgarisi, Valeri Frumkin, Omer Luria, Moran Bercovici
Summary: The method presented allows for shaping liquid volumes and solidifying them into desired freeform components with high surface quality, providing a rapid prototyping solution for high-quality components in the optical design industry. It has the potential to be expanded to an industrial scale for mold-less fabrication of freeform optics.
Article
Chemistry, Multidisciplinary
Raquel C. Goncalves, Sara Vilabril, Catarina M. S. S. Neves, Mara G. Freire, Joao A. P. Coutinho, Mariana B. Oliveira, Joao F. Mano
Summary: Compartmentalized structures obtained in all-aqueous settings have shown promising properties as cell encapsulation devices and reactors for trans-membrane chemical reactions. The interfacial stability conferred by emulsion systems enables the production of complex architectures. In this study, self-standing, malleable and perfusable tubular systems were fabricated through all-aqueous interfacial assembly, which can be used for cell culture and customized applications.
ADVANCED MATERIALS
(2022)
Article
Optics
Haisong Tang, Zexin Feng, Dewen Cheng, Yongtian Wang
Summary: We utilize Monte Carlo-based parallel ray tracing to quickly evaluate the irradiance of freeform lenses with non-uniform rational B-splines (NURBS) surfaces. By employing the inverse transform sampling method, we are able to uniformly sample rays from the Lambertian light source, while the analytical form of the B-spline basis function allows for fast surface interpolation. To ensure accurate calculations of ray-surface intersections, we propose a parameter transformation method to prevent parameter values from exceeding the defined range during the iteration process. Simulation results of two complex picture-generating freeform lenses demonstrate the speed and effectiveness of our method.
CHINESE OPTICS LETTERS
(2023)
Article
Chemistry, Physical
Xinyi Xiao, Hanbin Xiao
Summary: Robotic additive manufacturing faces challenges in terms of collision and support structure. We propose a systematic approach to automate the planning procedures and overcome these challenges. By integrating collision-avoidance conditions into the model decomposition step, we generate the entire workspace for the robotic additive building platform and enable autonomous manufacturing of large and complex metal components.
Article
Optics
Chuanxun Chen, Qun Hao, Jie Cao, Yingying Xu, Yang Cheng
Summary: This paper proposes a novel two-dimensional varifocal scanning element actuated by dielectric elastomer, which can change the focal length by moving two pairs of Alvarez lenses laterally and scan the imaging object in a two-dimension direction by shifting a pair of decentred lenses. The experiments verify the effectiveness of the proposed varifocal scanning imaging system, with a maximum focal length variation of 3.75 times, a maximum scanning angle of 14.18 degrees, and response times of 124 ms and 203 ms for rise and fall respectively. The proposed element is expected to be used in the fields of microscopy, biomedicine, virtual reality, etc.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Oliver Huerta-Carranza, Maximino Avendano-Alejo, Rufino Diaz-Uribe
Summary: The method uses optical deflectometry to measure the shape of freeform surfaces, displaying a non-uniform pattern of spots on an LCD monitor, reflecting it on the surface under test and recording the image. An iterative algorithm is then used to measure the surface and calculate the spherical and cylindrical dioptric powers of the PAL.
Article
Materials Science, Multidisciplinary
Bo Hong, Yuanyuan Qu, Yuxiang Hong, Menglong Li, Yeming Zou
Summary: In this paper, the device tuning accuracy is introduced into the wire-arc deposition model for the first time, establishing a wire-arc stable deposition model in micro-plasma arc directional energy deposition. A well-formed 40-layer curved metal sample with a high material area utilization ratio was achieved using the proposed model and optimized deposition parameters. This study provides theoretical guidance for improving the stability and deposition accuracy in micro-plasma arc freeform fabrication.
MATERIALS & DESIGN
(2023)
Article
Optics
Ingo Sieber, Richard Thelen, Ulrich Gengenbach
Article
Automation & Control Systems
Ulrich Gengenbach, Martin Ungerer, Liane Koker, Klaus-Martin Reichert, Peter Stiller, Stephan Allgeier, Bernd Koehler, Xiaoqi Zhu, Chengyuan Huang, Veit Hagenmeyer
Article
Chemistry, Analytical
Ingo Sieber, Richard Thelen, Ulrich Gengenbach
Summary: 3D inkjet printing technology in optics is just beginning to take off, with the formulation of a digital twin enhancing optical models for high-precision printing processes. The integration of geometrical measurement data into simulation models allows for the fabrication and performance simulation of optical components. Sensitivity analysis can be used to define acceptable tolerance budgets in the process.
Article
Engineering, Environmental
Lisa Petani, Lorenz Wuehrl, Liane Koker, Markus Reischl, Jonas Renz, Ulrich Gengenbach, Christian Pylatiuk
Summary: Ozone therapy has been established in clinical applications for decades, especially in treating infections or herniated discs. The experimental setup developed enables real-time measurement of ozone concentration in water with a spectroscopic sensor, facilitating the calibration and evaluation of new ozone sensors. Results from the spectroscopic sensor and colorimetric photometer show a strong correlation in ozone concentration measurement, and the ozone decay curves measured with the experimental setup align well with previous research.
OZONE-SCIENCE & ENGINEERING
(2022)
Article
Engineering, Chemical
Ingo Sieber, David Zeltner, Martin Ungerer, Achim Wenka, Tim Walter, Ulrich Gengenbach
Summary: Aerosol jet printing is an emerging manufacturing technology for printed electronics, offering smaller feature sizes and more uniform thickness of printed layers compared to inkjet printing. The new integrated principle allows ink atomization directly inside the print head, enabling compact design, printing in all spatial directions, and on-demand operation.
AEROSOL SCIENCE AND TECHNOLOGY
(2022)
Review
Materials Science, Multidisciplinary
Lisa Petani, Valerie Wehrheim, Liane Koker, Markus Reischl, Martin Ungerer, Ulrich Gengenbach, Christian Pylatiuk
Summary: The importance of biocompatibility in medical sensors is emphasized in this study, with a focus on sensors fully fabricated from biocompatible materials. Two exemplary sensors are evaluated for their biocompatibility in oxygen-ozone injection therapy, with one sensor showing the highest biocompatibility and compliance with important requirements. Additionally, biological characterization tests are necessary to validate biocompatibility for specific medical applications.
FLEXIBLE AND PRINTED ELECTRONICS
(2021)
Article
Chemistry, Analytical
Zehua Chen, Ulrich Gengenbach, Xinnan Liu, Alexander Scholz, Lukas Zimmermann, Jasmin Aghassi-Hagmann, Liane Koker
Summary: Printing technology and mounting technology enable the novel field of hybrid printed electronics. One challenge in establishing a hybrid printed system is finding a mounting process that meets the requirements of functional inks and substrates, especially low process temperature. This study proposes a standardized interconnection and an automated bump-less flip-chip mounting process using a room temperature curing conductive adhesive. The proposed process allows for fabrication of hybrid printed devices in larger batch sizes, enabling more comprehensive evaluation of device parameters.
Proceedings Paper
Computer Science, Artificial Intelligence
Lisa Petani, Robert Barth, Lorenz Wuehrl, Ingo Sieber, Liane Koker, Markus Reischl, Ulrich Gengenbach, Christian Pylatiuk
Summary: This paper presents a low-cost photometer set-up for measuring ozone concentrations with a fast response time. It provides a basis for the development of compact and cost-effective photometers for ozone gas measurement.
2022 IEEE-EMBS CONFERENCE ON BIOMEDICAL ENGINEERING AND SCIENCES, IECBES
(2022)
Proceedings Paper
Computer Science, Artificial Intelligence
Martin Ungerer, David Zeltner, Achim Wenka, Ulrich Gengenbach, Ingo Sieber
Summary: This paper presents the functional validation of a newly developed aerosol-on-demand print head using fluid dynamical modeling and simulation. In this concept, ink is atomized by ultrasonic excitation and focused by a sheath gas in a converging nozzle. The unique feature of this concept is the direct generation of aerosol within the print head, enabling on-demand operation. Computational fluid dynamics (CFD) is utilized to carry out a pre-manufacturing study to validate the functionality of the concept and determine a design-for-manufacture.
PROCEEDINGS OF THE 12TH INTERNATIONAL CONFERENCE ON SIMULATION AND MODELING METHODOLOGIES, TECHNOLOGIES AND APPLICATIONS (SIMULTECH)
(2022)
Proceedings Paper
Computer Science, Artificial Intelligence
Stephan Allgeier, Ulrich Gengenbach, Bernd Koehler, Klaus-Martin Reichert, Veit Hagenmeyer
Summary: Phase-measuring deflectometry (PMD) is an optical inspection technique used for full-field topography measurements of reflective sample surfaces. The method relies on analyzing specific patterns reflected on the sample surface. This paper presents a simulation framework for PMD to evaluate the effects of a deformed screen surface, showing the accuracy limits if a deformation model of the pattern screen is not explicitly included in the reconstruction process.
AUTOMATED VISUAL INSPECTION AND MACHINE VISION IV
(2021)
Article
Multidisciplinary Sciences
Alexander Scholz, Lukas Zimmermann, Ulrich Gengenbach, Liane Koker, Zehua Chen, Horst Hahn, Axel Sikora, Mehdi B. Tahoori, Jasmin Aghassi-Hagmann
NATURE COMMUNICATIONS
(2020)
Proceedings Paper
Engineering, Electrical & Electronic
Stephan Allgeier, Ulrich Gengenbach, Bernd Koehler, Klaus-Martin Reichert, Veit Hagenmeyer