We introduce a novel class of hybrid-anisotropic microstructures governed by a set of fully geometric-driven parameters, enabling comprehensive top-down control for cell shape, orientation, density, hybridity (open and closed configurations), and thickness. To realize this, we develop a computational framework that transforms the designed parameter space into Voronoi-based micro-tessellations for 3D hybrid-anisotropic cell structures. The numerical simulations and physical experiments are across multiple objectives, i.e., stiffness, strength, and weight. These results are obtained using only a single base material, demonstrating the versatility and applicability.

The Ford 8D method, also known as the team-oriented problem-solving (TOPS) approach, is a structured problem-solving methodology used to identify, analyze, and solve quality and reliability issues in manufacturing processes. It involves cross-functional teams working together to define problems, identify root causes, implement corrective actions, and prevent issue recurrence. This study applied the Ford 8D method to a semiconductor original equipment manufacturer (OEM) in Taiwan, focusing on avoiding yield declines caused by tester time domain reflection (TDR) in wafer testing. In this process, testers and probe cards are used to evaluate the electrical performance of dies on wafers, providing critical feedback to integrated circuit (IC) designers and manufacturers for data analyses and future improvements. The implementation of strategies, verified by the plan-do-check-act (PDCA) cycle, was standardized for future problem-solving efforts. As a result, the weekly impact time due to TDR issues was significantly reduced from 27 hours to 7.9 hours, reflecting a 70.74% improvement. This study highlighted the effectiveness of the Ford 8D method in improving manufacturing efficiency and reliability within the semiconductor industry.

When a management reserve occurs due to a design change in a company's outsourcing project, the additional cost is customarily only 2% to 10% of the original contract amount. If the management reserve exceeds the original contract amount by 20% to 50%, it reveals the imprudence of running the outsourcing project. Based on the company's policy requirements, an outsourcing project must finish the tender process by following the timeline of every work stage determined by the characteristics and environment of the project. This research studied the factors causing management reserve in an outsourcing project of the case company using the Six Sigma define, measure, analyze, improve, and control (DMAIC) method. The root cause was the lack of defining the specific responsibility in charge of unit, leading to insufficient communication between demand and executive departments as well as between project engineering and procurement departments in the preceding process. The preceding process must have a specific management procedure by redefining each unit's responsibility to avoid frequent design changes later. In addition, the procurement department estimated the reserve prices by analyzing the supplier's quotes using quantitative cost analysis. In the ultimate efficiency evaluation, this study verified that the improved procurement cases dramatically reduced circumstances of design change and management reserve and met the case company's due date.

This research studies production scheduling problems with stochastic customer demand for food processing factories to determine a multi-period production schedule that minimizes the total cost and achieves a predetermined customer service level. Based on the practical food processing conditions, this study constructs a mixed integer programming (MIP) mathematical model and applies chance constrained programming (CCP) to transform probabilistic constraints of customer demand into deterministic constraints of customer demand with the associated normal distributions. Using the numerical data, this research verifies the proposed methodology. For sensitivity analysis, the results show that increasing overtime hours decreases the total cost and enhancing customer service level increases the total cost. Furthermore, this study investigates the impacts of different forecasting and production schedules on out-of-stock costs, inventory costs, and both.

The lightweighting technology reduces the weight of a product while maintaining its performance, by adopting stronger and lighter materials, designing weight efficient structures, applying alternative joint methods, and/or using advanced manufacturing processes. Lightweighting not only increases energy efficiency, and saves natural resources and costs, but also improves product performance and explores new industry applications. Since the lightweight technology is changing the nature of advanced manufacturing, concurrent with this shift in materials and the corresponding changes in design and manufacturing processes is the need to train the workforce of today and tomorrow in these technologies. We present the collaboration between Washtenaw Community College and Wayne State University on a National Science Foundation (NSF) Advanced Technological Education (ATE) project to engage industry and educators in developing a talent pipeline and initial curriculum addressing the lightweighting technology at the high school, community college and university levels, to meet emerging industry needs for engineers and technicians. This paper reports the development and results of workshops for K-12 teachers and community college faculty, including the workshop agendas, materials, and analyses of participants' feedback.

In the face of challenges from its Chinese and South Korean rivals, Taiwanese manufacturers of thin-film transistor liquid crystal display (TFT-LCD) panels have lost their advantage in the international supply chain. Taiwan’s panel industry is struggling with exorbitant investment costs, economic uncertainty, and numerous competitors. To take the initiative and capture the market, the case manufacturer seeks new technology transfer from an international company. However, manufacturing defects after the introduction of this technology have resulted in a more than 7% defective rate of electrical performance. Therefore, this study applies a systematic methodology that consists of defining, measuring, analyzing, improving, and controlling (DMAIC), to redesign the manufacturing processes, thereby improving yield rates, reducing scrapping costs, improving customer satisfaction, and strengthening competitive advantage. The results show that after the case company followed the DMAIC steps, the manufacturing flaw—small black pits, was identified and resolved. The incidence of defects decreased from 7.14% to 0%. The case study validated that the Six Sigma DMAIC methodology could help companies improve their product yield rate.

A biologically inspired compound eye system is fabricated for the detection of object motion without the need for sophisticated image processing. The array of the artificial optical unit, called ommatidium, structurally and functionally mimics the natural compound eyes for motion detection. Each artificial ommatidium consists of polymer lenses, a light-guiding polymer cone, a 3D printing cladding, and a light intensity sensor to measure the change of light intensity during motion detection. To simplify the signal processing and improve the system reliability, low-cost light sensors, instead of CMOS/CCD arrays, are used for measuring the light intensity changes caused by object movement. The distance and speed of a moving metal ball of a pendulum were measured using the compound eye system. The measured results agree well with the theoretical analyses. The error between the measured and calculated speed is less than 2%.

New product development (NPD) is a process of interactions among multiple parties. With stronger competition in the electronic product market, reducing NPD cycle time has become a common important subject in the information technology (IT) industry. The main topic of this research is process improvements in the research and development (R&D) department of the case company by studying how product competitiveness can be enhanced in the current rapid proceeding technology industry. The process-oriented and hierarchical structure is used to analyze the processes of a new printed circuit board (PCB) design and test, and then a modified design chain operations reference (DCOR) model is introduced to explore problems and suggest corresponding solutions. This research also specifies a clear design chain structure for the case firm and improves its R&D process by brainstorming. The goal is to increase the case firm’s PCB design chain efficiency by shortening the delivery time and reducing the problems of risks arising during the NPD. Finally, this research reviews the essence of the design chain management, draws conclusions, and points out directions for future research.

This paper demonstrated a novel method that combines the 3D printing as well as polymer refill and surface tension to mimic the functional complex geometry of artificial apposition compound eyes. In recent years, the camera system inspired by the compound eye have attracted a lot of attention in recent years thanks to several advantages including a wide field of view, highly sensitive to detect moving objects, and fast response time.

The use of biobased materials for industrial and consumer products has received more and more attention because of the need for sustainability and to address the climate change. Biobased materials are renewable and derived from agriculture, silviculture, and terrestrial/aquatic microbial systems and have been used by humans for thousands of years in many aspects. To pursue technological edges and environmental benefits, the United States Government has been pushing for further development and applications of biobased materials. For further growth in this area, we have seen that there is a strong need for professionals from various backgrounds, including biology, chemistry, and engineering. However, to our knowledge, there are no exiting course series or degree programs on biobased materials in the US for engineering students and practicing engineers, as compared to the international counterparts. To address this issue, we developed and offered a new series of biobased materials courses to both college students and practicing engineers to provide them introductory information on biobased materials and potential opportunities. This series contains six courses including topics of biobased stock, bio-economy, bio-based materials and fuel, material properties and testing, as well as additive manufacturing and applications. These courses were taken in Fall 2015, Spring 2016, and Summer 2016 by more than 62 community college students (some of them have full time jobs) and 11 practicing engineers from General Motors. Four of the courses were integrated into a formal semester course delivered to Wayne State University students in Summer 2016. The participants in individual short courses obtained certificates of completion for potential career opportunities and advancements. In this paper, we present the contents and student feedback of this new series of biobased materials courses and discuss the future direction of this project.

In this paper, in-situ nanomechanical measurement and ex-situ morphology study were conducted to investigate the surface roughness effects of current collectors on the performance of thin film silicon anodes. The in-situ analysis quantifies electrochemical processes and associated mechanical stress such as silicon-lithium alloy formation during charge and discharge. Upon lithiation, after SEI formation (approximately below 0.35 V), both alpha-Si films deposited on the pristine and FeCl3-etched copper experience elastic deformation with a rapid rise of a compressive stress. The films begin to deform plastically after the stress reaches compressive yield strength. Upon delithiation, the alpha-Si on the pristine copper has shown to have stress dissipation at a tensile stress of 0.28 GPa. However, the tensile stress of the a-Si on the FeCl3-etched copper continues until the stress reaches 0.4 GPa at the end of delithiation. In addition, the silicon anode was found to form small islands on roughened current collector (instead of peel-off from fiat current collector), indicating the design of the current collector may play an important role in the performance of lithium ion battery.

The authors would like to change the affiliation for second author, Mohammadreza Eskandari, as listed in the original version of the article [...]

In this paper, silicon containing thick anode electrodes were investigated to provide a higher energy density and capacity for EV/HEV applications. In our study, a facile technique of adding a mechanical buffer between thick active material and current collector is proposed and tested by an in-situ measurement using white light interferometry. The electrodes with a modified structure deliver a significant improvement to mechanical stability as well as battery performance compared to conventional electrodes with the original structural design. Therefore, the methodology demonstrated here can probably be used to mitigate the deteriorating effect of mechanical failure in silicon-based electrodes, in which volume variation is usually considered as a severe issue, of lithium ion batteries.

Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes. The stereolithography allows the structures to be 3D printed with very fine resolution and desired shapes. The resin is then chemically modified to carbon using pyrolysis to enhance electrochemical performance. The electrochemical characteristics of 3D printing carbon electrodes are assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D printing carbon electrodes is much higher than the same sized platinum (Pt) electrode. In-vivo electromyography (EMG) recording, 3D printing carbon electrodes exhibit much higher signal-to-noise ratio (40.63 ± 7.73) than Pt electrodes (14.26 ± 6.83). The proposed biofabrication method is envisioned to enable 3D printing in many emerging applications in biomedical engineering and electronics.

Metamaterial leaky wave antennas (MTM-LWAs), one kind of frequency scanning antennas, exhibit frequency-space mapping characteristics that can be utilized to obtain a sufficient field of view (FOV) and reconstruct shapes in both remote sensing and microwave imaging. In this article, we utilize MTM-LWAs to conduct a spectrally encoded three-dimensional (3D) microwave tomography and remote sensing that can reconstruct conductive targets with various dimensions. In this novel imaging technique, we employ the linear sampling method (LSM) as a powerful and fast reconstruction approach. Unlike the traditional LSM using only one single frequency to illuminate a fixed direction, the proposed method utilizes a frequency scanning MTM antenna array able to accomplish frequency-space mapping over the targeted 3D background that includes unknown objects. In addition, a novel technique based on a frequency and polarization hybrid method is proposed to improve the shape reconstruction resolution and stability in ill-posed inverse problems. Both simulation and experimental results demonstrate the unique advantages of the proposed LSM using MTM-LWAs with frequency and polarization diversity as an efficient 3D remote sensing and tomography scheme.

The linear sampling method (LSM) is an effective method to detect complicated structures in a short time. In this paper, we develop a novel kind of LSM by means of metamaterial (MTM) leaky wave antennas (LWAs) to conduct spectrally-encoded three-dimensional (3D) microwave tomography that can reconstruct a conductive target with coaxial multi-layer and various diameter cylinders. The unique frequency-space mapping feature of MTM LWAs enables an efficient 3D microwave imaging with a larger field of view compared with conventional LSM approaches that usually operate at one single frequency. Validated through both theoretical analysis and experimental results, the proposed MTM imaging scheme allows us to reconstruct 3D shapes effectively with minimal prior knowledge of the target and computational resources. Furthermore, the measured results verify the proposed imaging method by successfully detecting the unknown targets with different shapes and locations for the MTM LWAs operating at 1.8–3 GHz.

This paper presents a novel approach for linear sampling method (LSM) to conduct remote sensing for radar applications, such as automotive radar sensors, by incorporating frequency mapping antenna array based on metamaterial leaky wave antennas (MTM-LWAs). Unlike traditional LSM using only one single frequency to illuminate in a certain direction, the proposed approach utilizes a frequency scanning MTM antenna array to perform frequency-space mapping over the targeted three dimensional (3D) background that includes unknown objects, resulting in a significantly increased field-of-view (FOV). The information obtained from the frequency-space scanning scheme is then transferred to the LSM analysis to detect the locations and shapes of the unknown objects. The proposed novel frequency scanning scheme in combination with LSM serves as an efficient 3D remote sensing scheme without the use of any phase shifters.

The linear sampling method (LSM) is a powerful and fast reconstruction approach and has shown capabilities of both remote sensing and tomography imaging in the microwave frequency range. In this paper, we report some recent advances in developing a novel kind of LSM by means of metamaterial (MTM) leaky wave antennas (LWAs) to conduct spectrally-encoded three-dimensional (3D) microwave tomography that can reconstruct a conductive target with coaxial multi-layer and various diameter cylinders. The unique frequency-space mapping feature of MTM LWAs enables an efficient 3D microwave imaging with a larger field of view compared with conventional LSM approaches that usually operate at one single frequency. It is shown that the LSM can also be used to conduct remote sensing for radar applications, such as automotive radar sensors, by incorporating frequency mapping antenna array based on MTM-LWAs. The proposed frequency scanning scheme in combination with the LSM in this article serves as an efficient 3D remote sensing scheme without the use of phase shifters.

In this paper, novel microwave gas sensors based on graphene-loaded substrate integrated waveguide (SIW) cavity resonators are presented. Two SIW-based cavity resonators, a ring-slot resonator and a complementary split ring resonator (CSRR), are fabricated and coated with chemical vapor deposited (CVD)-grown graphene. The fabricated graphene contains a layer of polymethyl methacrylate (PMMA) on its top. The graphene sheets exhibit high sensitivity to various kinds of polar and non-polar gases. When polar gas contacts the graphene sheet, it will donate or receive electrons, thereby changing its conductance. The SIW cavities thus perform a resonant frequency shift from the perturbation of electron exchange. In the experiment, a frequency shift of 59 MHz and 157 MHz for the SIW ring-slot resonator and CSRR, respectively, can be observed after pure ammonia gas is injected into a closed chamber filled with air at standard atmospheric pressure and temperature. This work demonstrates a very simple and efficient gas sensing scheme in the microwave regime. The proposed devices are promising to be further integrated with RF front-ends, providing a low cost and high sensitive gas sensing and environmental monitoring solution.

This paper presents a bilayer cantilever for sensitive and quantitative measurements of mechanical stress during electrochemical cycling in lithium ion batteries. The fabricated MEMS cantilever with anode material was tested in a customized liquid cell and its deformation associated with stress during charge/discharge was monitored by a white light interferometer. During lithiation (Li ion insertion), the maximum compressive stress was -0.35GPa at the cell voltage 165mV. During delithiation, the maximum tensile stress was 0.5GPa at 370mV. Both occurred in the first cycle. When the cell voltage was below 100mV during lithiation, major film cracking occurred, which lead to relieving compressive stress. The overall stress showed gradual reduction over the rest of cycles.