Measurement Studies Utilizing Similarity Evaluation between 3D Surface Topography Measurements

In the realm of quality assurance, the significance of statistical measurement studies cannot be overstated, particularly when it comes to quantifying the diverse sources of variation in measurement processes. However, the complexity intensifies when addressing 3D topography data. This research introduces an intuitive similarity-based framework tailored for conducting measurement studies on 3D topography data, aiming to precisely quantify distinct sources of variation through the astute application of similarity evaluation techniques. In the proposed framework, we investigate the mean and variance of the similarity between 3D surface topography measurements to reveal the uniformity of the surface topography measurements and statistical reproducibility of the similarity evaluation procedure, respectively. The efficacy of our framework is vividly demonstrated through its application to measurements derived from additive-fabricated specimens. We considered four metal specimens with 20 segmented windows in total. The topography measurements were obtained by three operators using two scanning systems. We find that the repeatability variation of the topography measurements and the reproducibility variation in the measurements induced by operators are relatively smaller compared with the variation in the measurements induced by optical scanners. We also notice that the variation in the surface geometry of different surfaces is much larger in magnitude compared with the repeatability variation in the topography measurements. Our findings are consistent with the physical intuition and previous research. The ensuing experimental studies yield compelling evidence, affirming that our devised methods are adept at providing profound insights into the multifaceted sources of variation inherent in processes utilizing 3D surface topography data. This innovative framework not only showcases its applicability but also underlines its potential to significantly contribute to the field of quality assurance. By offering a systematic approach to measuring and comprehending variation in 3D topography data, it stands poised to become an indispensable tool in diverse quality assurance contexts.This article is published as Liu, Lijie, Beiwen Li, Hantang Qin, and Qing Li. "Measurement Studies Utilizing Similarity Evaluation between 3D Surface Topography Measurements." Mathematics 12, no. 5 (2024): 669. doi: https://doi.org/10.3390/math12050669. Copyright: © 2024 by the authors. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

Fabrication of micro-scale radiation shielding structures using tungsten nanoink through electrohydrodynamic inkjet printing

Electronics components used in space and strategic missions are exposed to harsh radiation environments, which could cause operational malfunction of the system through lattice displacement or ionization effects. One potential solution is to use tungsten as radiation shielding. Tungsten is a very effective material in shielding electronic components and manufacturing gratings for x-ray imaging. However, intrinsic properties of tungsten (e.g. density, chemical/thermal inertness and hardness) post a significant challenge of fabricating the material into micro-scale and delicate structures, especially in electronic device fabrication. To address the problem, we designed a new tungsten nanoink and developed a straightforward approach to create tungsten micro-structures by 3D printing. Various microstructures down to 10 µm resolution have been patterned and fabricated by electrohydrodynamic inkjet (e-jet) printing using tungsten nanoink. By optimizing process parameters (voltage modality) and materials properties (ink formulation), the dimension and morphology of the structures can be precisely controlled. An AC-modulated voltage was employed during the e-jet printing process to make the patterns much more controllable and stable. Multi-layer tungsten lines were characterized by x-ray imaging and exhibited excellent absorption of x-ray radiation. With the same thickness, printed lines showed nearly 1/3 absorptivity of x-ray radiation of bulk tungsten, leading to significant radiation attenuation effectiveness. Tungsten nanoink is a new material used in e-jet printing that has not been reported in the literature to the best of authors\u27 knowledge. The study establishes a new methodology of manufacturing micro-nano scale shielding components for electronic devices and rapid prototyping of gratings and collimators in radiography for medical and inspection applications. The research also provides practical guidance to fabricate high melting-point metals via nanoink and micro/nano scale 3D printing

Activation and Assembly of Plasmonic-Magnetic Nanosurfactants for Encapsulation and Triggered Release

Multifunctional surfactants hold great potentials in catalysis, separation, and biomedicine. Highly active plasmonic-magnetic nanosurfactants are developed through a novel acid activation treatment of Au–Fe3O4 dumbbell nanocrystals. The activation step significantly boosts nanosurfactant surface energy and enables the strong adsorption at interfaces, which reduces the interfacial energy one order of magnitude. Mediated through the adsorption at the emulsion interfaces, the nanosurfactants are further constructed into free-standing hierarchical structures, including capsules, inverse capsules, and two-dimensional sheets. The nanosurfactant orientation and assembly structures follow the same packing parameter principles of surfactant molecules. Furthermore, nanosurfactants demonstrate the capability to disperse and encapsulate homogeneous nanoparticles and small molecules without adding any molecular surfactants. The assembled structures are responsive to external magnetic field, and triggered release is achieved using an infrared laser by taking advantage of the enhanced surface plasmon resonance of nanosurfactant assemblies. Solvent and pH changes are also utilized to achieve the cargo release

Similarity evaluation of topography measurement results by different optical metrology technologies for additive manufactured parts

The surface topographic measurements can be used by the additive manufacturing (AM) industry for in-situ quality inspection. However, disagreements may arise when we use different technologies to measure the topography of the same sample surface due to noise, sampling or optical properties of the sample surface, which may cause miscommunications or confusions between manufacturers. Thus, proposing methods for rating the similarities to match surface topographic data measured by various optical techniques is of crucial importance. This research investigates similarity evaluation methods for three-dimensional point-cloud topography data acquired by different technologies. Two different optical techniques (focus variation microscopy and structured light scanning) are used as testbeds. We propose two similarity evaluation methods for three-dimensional point-cloud data based on image distance method and Pearson’s correlation coefficient. The experimental results demonstrate that the proposed methods are effective and informative in determining whether the measured data are collected from the same sample, even though the measuring systems have different working principles and resolutions. This research facilitates our understanding of the discrepancies between different measuring systems, and meanwhile benefits a cyber-manufacturing system where unified inspection methods are unavailable among different manufacturers sharing the metrology data in cyber space

High-Sensitivity Fully Printed Flexible BaTiO3-Based Capacitive Humidity Sensor for In-space Manufacturing by Electrohydrodynamic Inkjet Printing

Long-duration exploration missions require a paradigm shift in the design and manufacturing of space architectures. Humidity is a basic but crucial parameter of the environment and human health that needs to be monitored. Flexible sensors are considered consumable and current manufacturing techniques are not applicable due to limits of the technology in a space environment, the operation cost, and the allowable space. In this paper, we demonstrated a case study of “In Space Production Applications (InSPA)”. Electrohydrodynamic (EHD) inkjet printing technology is capable of manufacturing circuits in micro-gravity due to its unique mechanism, to fabricate a high-sensitivity flexible humidity sensor. The sensor shows very competitive sensitivity and response time compared to other previous work. The wireless human respiratory monitoring circuits were built based on the sensor and showed good accuracy and sensitivity to monitor the respiratory rate and amplitude for humans.This is a manuscript of the article Published as Jiang, Liangkui, Wei Li, Rayne Wolf, Matthew Marander, Tyler Kirscht, Fei Liu, Jennifer M. Jones, Curtis Hill, Shan Jiang, and Hantang Qin. "High-Sensitivity Fully Printed Flexible BaTiO 3-Based Capacitive Humidity Sensor for In-space Manufacturing by Electrohydrodynamic Inkjet Printing." IEEE Sensors Journal (2024). doi: https://doi.org/10.1109/JSEN.2024.3400248. Copyright 2024, IEEE

Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing; FAIM 2014

Paper presented at the Proceedings of the 24th International Conference on Flexible Automation & Intelligent Manufacturing, held May 20-23, 2014 in San Antonio, Texas, and organized by the Center for Advanced Manufacturing and Lean Systems, University of Texas at San Antonio; Includes bibliographical references; This paper presents a direct fabrication of highly conductive silver tracks with sub-20 μm microstructures on glass substrates using electrohydrodynamic jet printing (EHD) based on alternative current (AC) voltage. A new AC-modulated EHD technique is presented and used in directly printing by generating a fine jet through a large electrical potential between the nozzle and substrate. In the presented technique of AC-modulated EHD, when charge accumulates on the ink meniscus at the nozzle, a fine jet down to nano scale can be generated. The variables of fabrication process, like plotting speeds, curing temperature and number of layers, were investigated to achieve reliable jet printing of conductive silver tracks. Topography and electrical property of printed tracks were characterized and verified. By using modulated AC-pulsed voltage, we are capable of printing high resolution continuous patterns on insulating substrates. In the study, we successfully applied EHD for fabrication of highly conductive silver tracks on glass substrate. It was the first time that sub-20 μm silver tracks were demonstrated with resistivity about 3.16 times than bulk silver. The presented technique can be used for direct printing of micro scale electronic circuits and device

Similarity quantification of 3D surface topography measurements

3D surface topography provides critical information about surface textures and has begun to be used in additive manufacturing applications such as in-situ 3D monitoring and sample porosity comparisons, etc. In this research, we establish a thorough framework to quantify the similarity of 3D surface topography measurements and determine whether they are from the same surface or not based on the frequency domain representations after 2D Fourier transformation. Two measurements portraying the same surface are defined as a matched pair while the others are unmatched. This framework quantifies the similarity effectively, provides a new perspective for surface topography similarity evaluation, and serves as a benchmark work in 3D surface topography feature extraction in the frequency domain. Our work has a great potential to benefit not only the quality assurance of AM but also many other communities where surface topography data is useful.This is a manuscript of an article published as Jiang, Yiqun, Shaodong Wang, Hantang Qin, Beiwen Li, and Qing Li. "Similarity quantification of 3D surface topography measurements." Measurement 186 (2021): 110207. DOI: 10.1016/j.measurement.2021.110207. Copyright 2021 Elsevier Ltd. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Posted with permission

Measurement Studies Utilizing Similarity Evaluation between 3D Surface Topography Measurements

In the realm of quality assurance, the significance of statistical measurement studies cannot be overstated, particularly when it comes to quantifying the diverse sources of variation in measurement processes. However, the complexity intensifies when addressing 3D topography data. This research introduces an intuitive similarity-based framework tailored for conducting measurement studies on 3D topography data, aiming to precisely quantify distinct sources of variation through the astute application of similarity evaluation techniques. In the proposed framework, we investigate the mean and variance of the similarity between 3D surface topography measurements to reveal the uniformity of the surface topography measurements and statistical reproducibility of the similarity evaluation procedure, respectively. The efficacy of our framework is vividly demonstrated through its application to measurements derived from additive-fabricated specimens. We considered four metal specimens with 20 segmented windows in total. The topography measurements were obtained by three operators using two scanning systems. We find that the repeatability variation of the topography measurements and the reproducibility variation in the measurements induced by operators are relatively smaller compared with the variation in the measurements induced by optical scanners. We also notice that the variation in the surface geometry of different surfaces is much larger in magnitude compared with the repeatability variation in the topography measurements. Our findings are consistent with the physical intuition and previous research. The ensuing experimental studies yield compelling evidence, affirming that our devised methods are adept at providing profound insights into the multifaceted sources of variation inherent in processes utilizing 3D surface topography data. This innovative framework not only showcases its applicability but also underlines its potential to significantly contribute to the field of quality assurance. By offering a systematic approach to measuring and comprehending variation in 3D topography data, it stands poised to become an indispensable tool in diverse quality assurance contexts

Development of a shelf-stable, gel-based delivery system for probiotics by encapsulation, 3D printing, and freeze-drying

A novel integrated manufacturing approach of encapsulation, extrusion-based 3D printing, and freeze-drying was applied to develop a shelf-stable, convenient product that maintained the viability of probiotics. The two selected strains of probiotic organisms, including Bifidobacterium lactis and Lactobacillus acidophilus, were encapsulated at 109–1010 CFU/g within 3, 5, and 7 g/100 g alginate-gelatin (A/G) hydrogels in different A/G ratios (1/2, 1/1, and 2/1). The B. lactis cell viability exceeded 109 CFU/g after 3D printing, with less than 1 log reduction throughout the integrated manufacturing process. The viability of B. lactis was maintained at a level larger than 6 log CFU/g upon 8 weeks of storage at room temperature. While L. acidophilus showed lower viability, with 106 CFU/g after printing, and up to 2.5 log reduction by the end of the integrated manufacturing processes. After freeze-drying, the 3D-printed products changed from a semi-solid to a solid-like state, confirmed by increased hardness and decreased water activity. This study demonstrated that an integrated manufacturing consisting of encapsulation, 3D printing, and freeze-drying has the potential to produce a shelf-stable, convenient snack food or supplement product that can deliver live probiotics with customized strains and dosage.This early view article is published as Kuo, C.C., Clark, S., Qin, H., Shi, X., Development of a shelf-stable, gel-based delivery system for probiotics by encapsulation, 3D printing, and freeze-drying. LWT, March 1 2022, 157(1 March 2022);113075. https://doi.org/10.1016/j.lwt.2022.113075. Posted with permission. (CC BY-NC-ND 4.0) Attribution-NonCommercial-NoDerivatives 4.0 Internationa