Albert J. Shih

The manufacturing of integrated circuits (ICs) is an enabler of technological innovation and is critical to the resilience of industry and national security. Four levels of excellence are necessary as the foundation for semiconductor manufacturing: ecosystem; fab profitability; IC design for manufacturing and research & development; culture and customer trust. In this paper, the culture, semiconductor manufacturing processes, innovations of equipment, removal processes, in-line metrology for process control, and data analytics are discussed. Future topics, including advanced packaging, sustainability, fab operation optimization, and in-space semiconductor manufacturing, as well as workforce policy and ethics, are elaborated.

This study investigates the smoothed particle Galerkin (SPG) method for modeling microcrack formation in diamond grinding of silicon carbide fiber-reinforced silicon carbide (SiC f /SiC) composites. The SPG method defines material separation by deleting inter-particle bonds rather than using element deletion or particle erosion as in finite element method or smooth particle hydrodynamics modeling. This bond-based failure model preserves the workpiece mass, enabling accurate and stable simulation of microcrack formation. Parallel computing, combined with an optimal domain decomposition strategy, is used to mitigate the extensive computational cost. SPG predicted microcracks align well with observations from scanning electron microscopy and transmission electron microscopy.

The growing need for sustainable, high-efficiency filtration materials has driven interest in biodegradable alternatives to polypropylene (PP)-based nonwovens, which dominate global production but generate severe environmental burdens. This study presents a comprehensive investigation of additive-free, low-viscosity biodegradable polylactic acid (PLA) melt-blown nonwovens, establishing relationships between processing parameters, fiber structure, crystallization, and electrostatic charging performance. Across 135 experiments, we reveal that die geometry, die-to-collector distance, polymer throughput, air pressure, and temperature jointly determine fiber morphology and crystallinity of PLA melt-blown nonwovens, thereby affecting the filtration performance. Clear process–structure–performance connections for PLA nonwovens were defined. PLA nonwovens with submicron fibers achieving >95% filtration efficiency at <160 Pa pressure drop were fabricated without post-charging, demonstrating the feasibility of scalable, biodegradable filter media. X-ray diffraction and thermal imaging reveal that in situ crystallinity can be tuned by air pressure, polymer throughput, and collection speed, which enhances thermal stability and supports long-term charge retention. Two-month charge decay tests further identify fiber diameter as the dominant factor in electret stability, with crystallinity playing a secondary but reinforcing role. By combining systematic experimentation with mechanistic insights, this work offers practical guidance for industrial-scale manufacturing of high-performance PLA nonwovens and advances the development of next-generation sustainable air filtration media.

Abstract Chronic total occlusion (CTO) is a cardiovascular disease in which coronary arteries are completely obstructed by atherosclerotic plaques for more than three months. Percutaneous coronary intervention (PCI) treatment of calcified CTO is challenging because hardened plaques prevent the crossing and delivery of microcatheters and balloons. In this study, a two-step atherectomy method for CTO treatment using a miniature electroplated nickel (Ni)-diamond wheel is proposed. The Ni-diamond wheel first drills a hole in the CTO lesion with rotational and oscillatory translational motion along a guidewire and then grinds the lesion using orbital motion to enlarge the hole beyond the diameter of the grinding wheel. The feasibility of the proposed two-step atherectomy method, combining drilling and grinding, and the forces exerted during drilling and grinding were experimentally investigated using two types of calcified CTO plaque surrogates: gypsum cement and ex vivo bovine bone. Drilling experiments were conducted in both manual and automated feeding modes. The experimental results demonstrate that the proposed miniature wheel drills through both types of CTO surrogates in the manual and automated feeding modes with more consistent drilling forces of approximately 0.046 and 0.027 N in the rapid and slow modes under automated feeding, respectively, than under manual feeding. During grinding, the miniature wheel generates orbital motion in the hole and expands the hole diameter from 0.85 to 1.26 mm within 120 s. The proposed integrated drilling and grinding approach has promise in addressing the clinical challenges of microcatheter- and balloon-uncrossable lesions in PCI treatment of CTO.

Lower-limb prosthesis (LLP) is critical for the mobility and quality of life of amputees. Ensuring the reliability and durability of LLPs is essential to users’ safety, comfort, and mobility. While the current standard (ISO 10328) for the mechanical test of LLPs has served as a foundation, the sinusoidal cyclic loading method used for fatigue testing does not replicate the actual loading conditions on LLPs during a human walking gait. In normal walking, LLPs are subjected to a dual-peak loading condition with two distinct force peaks at the heel-strike and toe-off phases. Such a cyclic and dual-peak dynamic loading pattern on LLP is essential to test the durability of the LLP effectively and reliably. In this study, two simple and effective dual-peak cyclic loading test apparatuses are designed and built to evaluate the durability and functionality of LLPs. Two loading plates are used to contact the heel and toe of the prosthetic foot to simulate the dual-peak heel-strike and toe-off loadings between the foot and the ground. This dual-peak loading on the LLP is controlled and replicated by adjusting the positions of two loading plates and the actuator stroke to change the contact forces. Experimental results show that the proposed testing apparatuses and procedures can emulate the dual-peak axial loading of the LLP during normal walking gait, providing a more accurate testing method of the dynamic loading condition on LLPs than the current ISO standard.

The U.S. manufacturing sector contends with an aging workforce, recruitment and retention challenges, and a strengthened national push for domestic production, leading to renewed calls for broadening workforce participation. Existing literature on broader engineering education suggests that both the focus of engineering curricula and student perceptions of a discipline’s career path likely impact workforce participation rates. To assess the current state of perceptions of manufacturing careers by undergraduate and graduate mechanical engineering students at an R1 public university, the authors of this paper collected and analyzed primary survey data in the 2023–2024 academic year. Perceptual differences existed between academic levels and between students with and without industry internship experience. Conversely, the findings revealed minimal differences in the perceived appeal and importance of manufacturing competencies and skills across racial and gender identities. Additionally, university courses and industry internships were identified as the primary factors influencing students’ perceptions of manufacturing careers. We propose that early exposure in mechanical engineering courses to real-world experiences that encompass a variety of manufacturing skillsets could foster more accurate career perceptions and potentially enhance participation rates.

A transient flow model is developed to predict the flow of high-viscosity fluid dispensing for precision direct ink writing (DIW) in additive manufacturing. Models for pump deformation and fluid friction to accurately predict flow of a high-viscosity non-Newtonian fluid through a progressive cavity pump, static mixer, and a tapered nozzle are created. Inside the progressive cavity pump, the effect of elastic deformation on modeling high-viscosity fluid transient flow is included. Based on the Characteristic Method (CM) and boundary conditions for DIW, the continuity and momentum equations are numerically solved. Using deformation modeling and CM, the transient response of the DIW system to the input volumetric flow rate is modeled for both a pipe and static mixer. The transient response of the DIW output volumetric flow rate is recorded using flow and pressure sensors and found to match the flow model. The deformation and CM models are applied to predict the swelling of a 90° corner DIW tool path from trapezoidal motion planning with accelerations from 100 to 2000 mm/s 2 . Predicted corner swelling is matched with the actual corner swelling via image processing of the 90° corner. The corner swelling is significant, ranging from 0.76 to 0.37 mm for a line width of 0.25 mm and a height of 0.15 mm, and represents the model’s ability to quantify print errors. This study demonstrates that the flow model can accurately predict the transient response of the DIW volumetric flow rate, which is foundational to high-fidelity flow control and compensation in precision DIW.

Background: Interventional therapies to relieve chronic deep vein thrombosis (DVT) fail through inability to penetrate, cross, and remove the occlusion. Development of suitable tools requires fundamental understanding of chronic DVT mechanical properties and a reliable model for testing. Methods: Female farm swine underwent a novel, endovenous generation of long-segment unilateral iliac vein thrombosis. Thrombus was confirmed via venogram, intravascular ultrasound, and transabdominal duplex for 14 days. Thrombus components were quantified via histology. Thrombus mechanical properties were assessed via uniaxial compression. Results: Among seven swine, technical success was 100%. Compared to subacute thrombi (7-day), chronic thrombi (14-day) showed organizing thrombus with diffuse myointimal thickening and collagen matrix formation on histology. The thrombi collagen content was 41% versus 55% ( p = 0.17) and the thrombus erythrocyte percentage was 4.3% versus 2.2%, p = 0.21 in 7- versus 14-day thrombi, respectively. The onset point (compression required to load the thrombus fiber network) was 66.6% versus 35.3% ( p = 0.004), the secant modulus (resistance to deformation) measured at the onset point was 153.8 versus 275.99 kPa ( p = 0.18), and the average shear constant (resistance to shearing), as defined by the Yeoh hyperelastic model, was 1.85 kPa versus 2.85 kPa in 7- versus 14-day thrombi. Conclusions: This study demonstrates the feasibility of an endovenous model generating chronic unilateral venous thrombi in 2 weeks with similar anatomy to humans and provides critical mechanical properties of thrombi for future research.

BACKGROUND: Plagiocephaly, wherein infants' head exhibits a diagonal asymmetry, is currently diagnosed based on physicians' subjective judgment. Discrepancies between physician and parent perspectives may result in dissatisfaction with treatment outcomes. This problem highlights the need for an objective assessment system aligning with physician-made clinical diagnoses. METHODS: Infant heads were modeled using 3-dimensional scanning techniques. We developed a craniofacial asymmetric index (CAI) based on 10 height planes of heads with varying weight. CAI and traditional craniofacial vault asymmetry index (CVAI) of 10 infants undergoing helmet therapy were compared with 11 craniofacial surgeons' judgment. The Pearson correlation coefficient and Bland-Altman plot were used to determine the correlations and agreement between physicians' judgment and the aforementioned assessment methods. The adjusted intraclass correlation coefficient was calculated to evaluate the reliability of between-physician agreement. RESULTS: All 10 infants were divided into the following 3 severity groups: severe, moderate, and mild groups based on craniofacial surgeons' judgment. Notably in CAI, front/back halves of skull and multiangular weighting factors were evaluated. The evaluation revealed perfect alignment in severity classification between the CAI and physicians' judgment, whereas both the CVAI score and MATLAB analysis show varying degrees of difference, 6 and 4 distinct results, respectively. Coefficients of the correlations of physician-assigned scores with the MATLAB analysis, CVAI score, and CAI score were 0.500, 0.833, and 1.000, respectively. Furthermore, Bland-Altman plots revealed the best agreement between CAI and physician-assigned scores. CONCLUSIONS: CAI closely aligns with the subjective judgment of craniofacial surgeons' assessing the severity of plagiocephaly in infants.

Chinedum OkwudireChinedum OkwudireThe 19th ASME International Manufacturing Science and Engineering Conference (MSEC 2024), sponsored by the Manufacturing Engineering Division (MED) of ASME, was held from June 17, 2024 to June 21, 2024 in Knoxville, TN. New to the MSEC 2024 technical program was the introduction of brief papers in addition to full-length papers. Brief papers are styled after the technical briefs of the Journal of Manufacturing Science and Engineering (JMSE). Brief papers undergo full peer review and are published in the conference proceedings in the same manner as full papers. However, they are shorter in length than full papers and, therefore, can be used to report preliminary research results for early feedback from the manufacturing community.MSEC 2024 received 238 submissions—102 (42%) brief papers and 137 (57%) full papers. After rigorous peer review, 204 technical papers—91 (45%) brief papers and 113 (55%) full papers—were accepted for publication. The technical papers had global representation, with authors from 22 countries across five continents, including the US, China, Germany, Australia, Brazil, and South Africa.Among the accepted technical papers, MSEC symposium organizers nominated 16 full papers to be fast-tracked to the JMSE. All of the papers, together with their reviews, were sent to the JMSE Editor-in-Chief for a new round of journal paper review. A total of eight top MSEC full papers received positive journal reviews and were compiled and published in this JMSE Special Section on MSEC 2024. The papers selected for this special section cover a wide range of topics. They come from technical tracks of the ASME MED, including advanced materials manufacturing, biomanufacturing, life cycle engineering, manufacturing processes, nano/micro/meso manufacturing, and quality and reliability.As a leading international conference held annually on manufacturing process technology, MSEC acts as a global bridge between industry, government laboratories, and academic institutions. This Special Section showcases recent manufacturing research advancements presented at MSEC 2024. It also provides a platform for researchers and practitioners to widely disseminate their research findings and innovative practices that may inspire future scientific and technological breakthroughs.Albert ShihAlbert ShihWe would like to thank all of the symposium organizers of MSEC 2024 for their dedicated management of the symposia and for guarding the quality of the papers to be fast-tracked, which has contributed a great deal to the success of this Special Section. We would also like to thank all of the reviewers of the paper submissions for their detailed suggestions to improve the papers' quality. Special thanks are to the ASME MED Executive and Technical Committees and the ASME staff, especially Lori Lee and Elizabeth Bruce. Their outstanding contributions in managing the submitted technical papers ensured the high-quality publication of this Special Section for MSEC 2024.JMSE continues to seek close partnerships with MED and MSEC to serve our manufacturing community. Authors of accepted JMSE papers published between Mar. 2023 and Feb. 2024 were offered the opportunity to present their papers at MSEC 2024. A record number of 20 authors selected this option and presented their journal-quality research work in MSEC 2024. This has expanded the opportunity for colleagues in our manufacturing community to submit their top research papers to JMSE and then disseminate them in a presentation to our manufacturing community at MSEC.This Special Section marks another important step for JMSE to connect with MED and MSEC. As the brief papers get more established at MSEC, we envision future brief papers being fast-tracked to JMSE technical briefs. Future Technical Program Chairs and JMSE Editors will continue to make this a seamless process. JMSE seeks top research papers from our colleagues and strives to serve our community as a platform for the timely publication of high-impact research work.

Background: Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension (CTEPH) is limited by a lack of safe and effective tools for crossing these lesions. We aim to identify a safety window for an intraluminal crossing device in this vascular bed by studying the piercing properties of pulmonary arterial vessel walls and intraluminal CTEPH lesion specimens. As a secondary objective, we also describe the histopathologic features of CTEPH lesions. Methods: Specimens were procured from 9 patients undergoing pulmonary endarterectomy. The specimens were subsampled and identified grossly as arterial wall or intraluminal CTEPH lesions. The force needed for tissue penetration was measured using a 0.38-mm (0.015-in) diameter probe in an ex vivo experimental model developed in our lab. Concurrent histology was also performed. Results: < .001). Histology confirmed the presence of intimal hyperplasia with calcium and hemosiderin deposition in the arterial wall as well as an old, organized thrombus in the lumen. Conclusions: The pulmonary arterial wall is friable and prone to perforation during instrumentation with workhorse coronary guide wires. However, the results of this study demonstrate that a much lower force is needed for the 0.38-mm (0.015-in) probe to penetrate an intraluminal CTEPH lesion compared to pulmonary arterial intima. This finding suggests the existence of a safety window for lesion-crossing devices, enabling effective balloon pulmonary angioplasty.

Purpose 3D-printed devices proved their efficacy across different clinical applications, helping personalize medical treatments. This paper aims to present the procedure for the design and production of patient-specific dynamic simulators of the human knee. The scope of these simulators is to improve surgical outcomes, investigate the motion and load response of the human knee and standardize in-vitro experiments for testing orthopedic devices through a personalized physical representation of the patient’s joint. Design/methodology/approach This paper tested the approach on three volunteers. For each, a patient-specific mathematical joint model was defined from an magnetic resonance imaging (MRI) of the knee. The model guided the CAD design of the simulators, which was then realized through stereolithography printing. Manufacturing accuracy was tested by quantifying the differences between 3D-printed and CAD geometry. To assess the simulator functionality, its motion was measured through a stereophotogrammetric system and compared with the natural tibio-femoral motion of the volunteers, measured as a sequence of static MRI. Findings The 3D-printing accuracy was very high, with average differences between ideal and printed parts below ± 0.1 mm. However, the assembly of different 3D-printed parts resulted in a higher average error of 0.97 mm and peak values of 2.33 mm. Despite that, the rotational and translational accuracy of the simulator was about 5° and 4 mm, respectively. Originality/value Although improvements in the production process are needed, the proposed simulators successfully replicated the individual articular behavior. The proposed approach is general and thus extendible to other articulations.

PURPOSE This study investigated dimension changes of various nasopharyngeal airways, including a novel self-supporting device, after saline submersion at body temperature to simulate in-vivo use. Dimension changes over time may reduce efficacy during long-term use and require sizing adjustments or limits on duration of use. MATERIALS AND METHODS Cuffless Covidien endotracheal tubes, pediatric Rusch fixed flange polyvinyl chloride nasal airway tubes, pediatric Rusch Robertazzi style Mediprene nasal airway tubes, and novel silicone elastomer self-supporting nasopharyngeal airways were fully submerged in 0.9 % normal saline solution incubated at 37 degrees Celsius for 15 days. All devices had tube length and wall thickness measured after 0, 1, 2, 3, 4, 5, 10, and 15 days. The 95 % confidence intervals of tube dimensions at each date were compared with the 95 % confidence intervals at day 0. RESULTS The Covidien ET tube, Rusch PVC NPA, and ssNPA tube lengths and wall thicknesses did not change significantly over 15 days. The Rusch Mediprene NPAs had a statistically significant increase in length starting at day 1 and wall thickness at day 2. CONCLUSIONS The novel ssNPA did not expand in the in-vitro environment, supporting its safety for extended use. The PVC NPA and ET tube dimensions also remained stable. However, the Rusch Mediprene NPAs had significant length expansion after 1 day of submersion, indicating a considerable risk of expansion during extended use with potential implications for patient care. Silicone and PVC NPA dimensions remained stable when saturated, indicating these materials may be more appropriate for extended use.

Robotic high-viscosity fluid deposition plays a pivotal role in various manufacturing applications including adhesive and sealant dispensing, as well as in the additive manufacturing of deformable materials, such as those employed in soft robotics. Uncompensated high-viscosity fluid deposition can lead to poor part quality and defects due to large transient delays and complex fluid dynamics. In this letter, we propose a lumped-parameter flow model and compensation strategies to address significant transient delays and nonlinearity inherent in high-viscosity fluid deposition using a robotic manipulator. Our computationally efficient model is well-suited to real-time control and can be calibrated in minutes. Our compensation strategies leverage an iterative Linear-Quadratic Regulator to compute compensated deposition paths that can be deployed on robotic dispensing systems. These paths can either be deployed offline or corrected live via feedback from our proposed vision-based flow sensor. To validate the effectiveness of our approach, we conducted experiments extruding high-viscosity liquid silicone using a Kuka lbr iiwa robot. Comparative analysis with several baseline protocols demonstrates that our proposed method significantly improves material deposition within desired boundaries.

Research over the last 70 years has led to a better understanding of fixed-abrasive machining processes. This knowledge is often expressed in the form of physical and empirical models that cover forces, power, specific energy, wheel/workpiece topography, wear, thermal aspects, cooling, dressing, and more. This paper first examines the established models that continue to constitute the fundamental knowledge base in fixed-abrasive technology. Special attention is given to geometry, kinematics, and thermomechanical modeling. Recent advances in process monitoring and big data analytics provide new opportunities to further strengthen the state of the art in modeling through data-driven approaches. In addition, examples on how models – implemented in simulation software – can be used to predict and optimize industrial operations have been demonstrated. This is illustrated by several use cases from real production, including bearing, creep-feed form, gear, camshaft, crankshaft, and centerless grinding, along with diamond-wheel truing.

GOAL: This work examines the use of a previously described piecewise continuous lumped muscle parameter (PPCLMP) model for predicting selected gait parameters for walking without and with ankle-foot orthoses (AFOs) of varying stiffnesses. METHODS: Two AFOs with low (3.4 Nm/deg) and high (6.9 Nm/deg) stiffnesses were tested on the left leg of six healthy subjects to examine the model prediction on the influence of different AFO stiffnesses on gait. RESULTS: The model prediction errors ranged from 0 % to 70 % for step lengths with root mean square error (RMSE) of 0.15 m and ranged from 0 % to 67 % for swing time with RMSE of 0.07 s. The prediction precision of step length was more consistent among subjects than of swing time. DISCUSSIONS AND CONCLUSIONS: The model predicts the observed shortened step lengths and swing times, but there were significant differences between predicted and observed swing times and step lengths. The causes of these differences might be differences in the lumped muscle parameters taken from the literature and those of the subjects tested. Also, the model assumption that muscle stiffness is proportional to joint angle may not be corrected.

Albert Shih, Editor-in-ChiefAlbert Shih, Editor-in-ChiefThe objective of this Special Issue is to connect the ASME Journal of Manufacturing Science and Engineering (JMSE) and European manufacturing researchers through a collection of articles on high-level scientific work in manufacturing. It provides an opportunity for European researchers to present their state-of-the-art research results in manufacturing. In addition to the scientific aspect, the aim of this Special Issue is to bring together two of the world’s leading scientific communities. Indeed, although JMSE is an American journal, the European community needs to be shown in this historical and prestigious journal, and this rapprochement is one of the motivations behind this Special Issue. This Special Issue is also a good way of exchanging ideas between researchers in Europe and around the world.A team of Guest Editors has been setup to collect as many interesting articles as possible. The team is led by Dr. Vincent Wagner (ENI de Tarbes, France) and consists of Professors Pedro Jose Arrazola (Mondragon Unibertsitatea, Spain), Yuebin Guo (Rutgers, The State University of New Jersey, New Brunswick, NJ), Knut Sorby (Norwegian University of Science and Technology, Norway), Franci Pusavec (University of Ljubljana, Slovenia), Andreas Klink (RWTH Aachen University, Germany), and Michael Schmidt (Friedrich-Alexander Universität Erlangen-Nürnberg, Germany).The collection of articles is from Jan. 2023 to July 2023. In collaboration with the associate editors, each article underwent a rigorous peer review process, which is a hallmark of JMSE. The articles selected in this Special Issue are from France, Germany, Italy, Austria, Finland, England, Scotland, Belgium, Spain, Norway, and Turkey. We are delighted to see three inter-European collaborations and four global collaborations (Europe–USA and Europe–Asia).Although this collection of articles is not exhaustive, it represents the state of advanced manufacturing research currently being carried out in Europe. A broad range of topics including additive manufacturing, machining, assembly/joining processes, robotics and cobotics, machine learning in manufacturing, and non-destructive testing is presented. These articles and the subjects they cover are a succinct overview of the knowledge acquired in Europe and of the topics addressed.Vincent Wagner, Guest EditorVincent Wagner, Guest EditorThis special issue is the beginning of a long and strong collaboration between JMSE and European researchers. In the past few months, we already have received enough new submissions from Europe for another JMSE European Special Section. This JMSE-Europe collaboration will continue.The Editor-in-Chief would like to acknowledge Professors Kornel Ehmann and Yuebin Guo, who both provided this idea of engagement with Europe during the consultation process before he started as the editor in July 2022. We also want to acknowledge Emily Bosco, who provides continuous and timely editorial assistance.

Abstract This paper summarizes the perspectives from a manufacturing engineer on how the government policy, global partnership, and diversity of the United States (US), Japanese, European, and traditional Chinese cultures in Taiwan have created a workforce of semiconductor manufacturing talent in the past five decades. The complex interwoven events of Covid-19 pandemic, supply chain resilience, national security, and geopolitical conflicts have made semiconductor manufacturing a key focus of government policy. As a world leader in integrated circuit (IC) design, design software, equipment, and research, the US has struggled in the past few years on the high yield volume manufacturing of the most advanced logic IC and failed to translate research innovations to quality production. Manufacturing, not innovation or equipment, is a key barrier of the US semiconductor industry. Two models for excellence in advanced manufacturing are described. Three pillars of government policy, global collaboration, and multicultural diversity empower semiconductor manufacturing excellence in Taiwan is described. An approach to evaluate, select, educate, and train manufacturing talents is proposed. Directions for semiconductor manufacturing research are discussed. There is no genius in semiconductor manufacturing, which requires extensive experience and continuous improvement without shortcuts to be competitive. The steadfast good government policy, multicultural diversity workforce, and global technology collaboration to achieve semiconductor manufacturing excellence are the focus of the conclusion.

Albert Shih, Editor-in-Chief, JMSEAlbert Shih, Editor-in-Chief, JMSE The Journal of Manufacturing Science and Engineering (JMSE) is actively soliciting research papers in semiconductor manufacturing. A Special Issue in "Semiconductor Manufacturing" is planned to publish in Summer 2024 with Cha Bum Lee, Martin Jun, Greg Vogl, Sangkee Min, and Jichul Yang as Guest Editors. In her speech entitled "The CHIPS Act and a Long-term Vision for America's Technological Leadership" at Georgetown University on February 23, 2023, US Secretary of Commerce Gina Raimondo said, "Semiconductors form the foundation of all advanced technology." She elegantly outlined the historic opportunity and the long-term goals provided by the CHIPS and Science Act. By searching the keyword "manufacturing" in her speech, you may read:"manufacturing—not software or algorithms—powered this engine of innovation.""We once manufactured nearly all of the world's most advanced semiconductors. Today, we manufacture none. Taiwan alone produces 92% of the world's leading-edge chips.""We sacrificed our manufacturing capacity and workforce in the mistaken belief that we could somehow maintain our technological leadership without them.""This manufacturing atrophy has real consequences … it's a threat to our national security.""If we don't invest in America's manufacturing workforce, it doesn't matter how much we spend… It starts with training and inspiring a generation of engineers and scientists who are excited about manufacturing."We have a once-in-a-generation opportunity in advanced manufacturing. I wrote a unique JMSE article entitled "Multicultural Diversity Workforce and Global Technology Collaboration Empowered Semiconductor Manufacturing Excellence in Taiwan: A Manufacturing Engineer's Perspective" in this Issue summarizing my observations and hypotheses on why Taiwan is so good in semiconductor manufacturing. In the past nine months at National Tsing Hua University (NTHU) in Hsinchu, a city where Taiwan started the pursuit and continued relentless R&D to maintain the lead in semiconductor manufacturing excellence, I am surrounded by many outstanding semiconductor manufacturing and R&D engineers. This article is a reflection of the wisdom of many of them. I was also hoping to be close to my ailing mother, who unfortunately passed away before I started at NTHU. In hindsight, her illness made possible this JMSE article, which is dedicated to her."Multicultural diversity" is a key message of this JMSE article, which will be informative for manufacturing engineers and laypersons by demonstrating the impact and importance of diversity and showing the complexities, challenges, and opportunities in semiconductor manufacturing. It is my greatest hope that this JMSE article will inspire the multicultural diversity aspects in our society and encourage more colleagues to study frontier semiconductor manufacturing.This issue has three other papers with authors from Taiwan on power skiving, an advanced internal gear cutting process, and silicon nanowire manufacturing. Altogether, this is a Special Section dedicated to advanced manufacturing in Taiwan.

Direct ink writing is used to print multiple polydimethylsiloxane (PDMS) mixtures with fumed silica or as a two-part commercial liquid silicone rubber (LSR) mixed with polyethylene glycol (PEG) or as a two-part commercial vulcanizing (RTV) silicone. We correlate their printability into a hollow slump cone with rheological measurements, including (1) a shear rate up-ramp followed by (2) a down-ramp in the shear rate, (3) creep tests, and (4) large-amplitude oscillatory shear (LAOS) with increasing amplitude. The PDMS-fumed silica mixtures fail to print even at the highest fumed silica loading used (9 wt. %), while LSR-PEG with 4 or 6 wt. % PEG prints well, and one of the two RTV silicone components is printable, as is the mixture due in part to its rapid chemical curing. The large differences in printability of these materials do not correlate well with any single rheological test. They do correlate with a combination of a measure of material strength, given by either the yield stress σycr from creep tests or the “flow stress” σf at which G′ and G″ cross-over in LAOS, and of material recoverability given by the dynamic yield stress σy− in test 2. The latter is measured during a down-ramp in the shear rate after reaching a maximum shear rate of 1000 s−1, the highest shear rate in the print nozzle.

Abstract Objective. Carbon fiber (CF) is good for chronic neural recording due to the small diameter (7 µ m), high Young’s modulus, and low electrical resistance, but most high-density carbon fiber (HDCF) arrays are manually assembled with labor-intensive procedures and limited by the accuracy and repeatability of the operator handling. A machine to automate the assembly is desired. Approach. The HDCF array assembly machine contains: (1) a roller-based CF extruder, (2) a motion system with three linear and one rotary stages, (3) an imaging system with two digital microscope cameras, and (4) a laser cutter. The roller-based extruder automatically feeds single CF as raw material. The motion system aligns the CF with the array backend then places it. The imaging system observes the relative position between the CF and the backend. The laser cutter cuts off the CF. Two image processing algorithms are implemented to align the CF with the support shanks and circuit connection pads. Main results. The machine was capable of precisely handling 6.8 μ m carbon fiber electrodes (CFEs). Each electrode was placed into a 12 μ m wide trenches in a silicon support shank. Two HDCF arrays with 16 CFEs populated on 3 mm shanks (with 80 μ m pitch) were fully assembled. Impedance measurements were found to be in good agreement with manual assembled arrays. One HDCF array was implanted in the motor cortex in an anesthetized rat and was able to detect single unit activity. Significance. This machine can eliminate the manual labor-intensive handling, alignment and placement of single CF during assembly, providing a proof-of-concepts towards fully automated HDCF array assembly and batch production.

3D printing for custom prosthetic finger fabrication can have better fit and comfort than non-custom off-the-shelf ones while reducing fabrication labor time. The purpose of this case study was (1) to design and fabricate custom prosthetic fingers using 3D-printed molds for the treatment of partial finger amputation; (2) to evaluate patient satisfaction of the custom prosthetic fingers fabricated using 3D-printed molds and compare them to the custom prosthetic fingers fabricated through a conventional method of molding using plaster casts. The method to develop the custom prosthetic finger are as follows: (1) The shapes of the residual digits and contralateral fingers were acquired using a high-resolution 3D optical scanner. (2) Prosthetic fingers were designed by modifying the model of the residual digits and the contralateral fingers. (3) Molds of the prosthetic fingers were designed using computer-aided design software and fabricated by 3D printing. The study compared hand function tests and rehabilitation outcome surveys to evaluate the performance of the prosthetic fingers fabricated using 3D-printed molds and plaster casts. This case suggests that the prosthetic fingers fabricated using 3D-printed molds had comparable performance to the prosthetic fingers fabricated using plaster casts. The aesthetics and transparency of the prosthetic fingers contributed highly to the low satisfaction of the prosthetic fingers fabricated using 3D-printed molds.

ABSTRACT Introduction The study presents the design and manufacturing of a custom silicone distal cup, with a high spatial resolution, to fit inside the prosthetic liner for the treatment of irregular morphology at the distal residual limb of a patient with lower-limb amputation. This distal cup for the inside of the prosthetic liner has intricate interior features matching the shape of the distal residual limb to prevent localized high-pressure regions. Methods High-resolution 3D optical scanning, computer-aided design (CAD), and material extrusion (MEX) process for additive manufacturing of molds are three key techniques for designing and manufacturing this custom distal cup. A three-part mold for molding the distal cup with matching features was designed by CAD and fabricated by MEX. The subject evaluated the distal cup by walking using the distal cup before wearing the prosthetic liner in the lower-limb prosthesis. Results A custom silicone distal cup was fabricated using a 3D-printed mold and evaluated using a Prosthetic User’s Survey. Based on the survey, the insert has an acceptable comfort, suspension requirement, and ease of use. Conclusions The scan by high spatial resolution Space Spider optical scanner could capture detailed features of the distal residual limb. The resulting distal cup had the protrusion that functioned to separate the invaginations. The subject was satisfied with the distal cup based on the Prosthetic User’s Survey. Clinical Relevance The approach to fabricate the custom silicone distal cup using a high-resolution 3D optical scanner and a 3D-printed mold can be applied to fabricate the distal cup with intricate features for a patient with irregular morphology at the distal residual limbs.

Journal of Manufacturing Science and Engineering (JMSE) welcomes Position Papers from manufacturing science and engineering thought leaders. The position paper points to a new frontier research direction for simple and innovative thinking and provides examples and a roadmap for manufacturing research. A position paper aims to inspire our manufacturing research community by sharing novel and bold ideas to address national and global challenges for long-lasting impacts.In this issue, we are delighted to publish a position paper by Malshe, Bapat, and Fischer on “Understanding Frugal Engineering for Equity: Exploring Convergence of Biological Designs and Social Innovations.” Against the backdrop of years of advanced manufacturing R&D, multiple global trends and drivers have resulted in a steep escalation of tech-socio-economic inequities in basic human needs across industrialized as well as industrializing nations. This escalation is paralleled by the growing trend of novel and simple frugal innovations for meeting basic human needs, which are applied across various communities in the world toward bridging gaps of inequity. “Frugality” in this context is defined as minimizing the use of capital resources while delivering effective manufacturing product outcomes. It is noteworthy that frugal innovations are abundantly observed in the biological designs in nature. This position paper is aimed at understanding the methodology of frugal engineering behind the resulting frugal manufacturing innovations through discovering the cross section of frameworks of biological designs in nature and equitable social innovations. Authors have applied the framework of biological designs as these designs are observed to deliver multifunctionality, resilience, and sustainability, which are key to a frugal and equitable innovation platform and achieved by the frugal engineering process.In 2008, a position paper on “Biomedical Manufacturing: A New Frontier of Manufacturing Research” introduced our community to a rich, new frontier of manufacturing research area with healthcare. Advanced manufacturing technologies, such as manufacturing processes, systems, and quality control, can be readily applied to improve the safety, quality, cost, efficiency, and speed of healthcare service and biomedical research. There is a biomanufacturing technical track created under the manufacturing engineering division (MED) and symposia for the exchange of research findings at the Manufacturing Science and Engineering Conference (MSEC).We want to encourage leaders of our manufacturing community, particularly those forward thinkers at the cusp of a new field, to write position papers for JMSE. We envision these position papers will spark new research in fundamentals of frugal engineering methodologies and equitable manufacturing and facilitate agility of manufacturing discipline to benefit society and deliver tech-socio-economic equity.

A miniature grinding wheel (0.85 mm diameter) was fabricated by nickel (Ni)-diamond electroplating on a thin (0.65 mm outer diameter) flexible hollow stainless steel drive shaft to remove the calcified plaque in coronary and peripheral arteries by atherectomy procedure. To coat electrically nonconductive diamond grits, the drive shaft was submerged in a pile of diamond grit during Ni electroplating. The electroplating current density and temperature were investigated for better surface finishing and Faraday efficiency. The electroplating time to obtain the designed coating thickness was modeled based on Faraday's law of electrolysis and the geometry of drive shaft, wheel, and diamond grit. To validate the miniature wheel performance in atherectomy, grinding experiments were conducted on an atherectomy cardiovascular simulator with a calcified plaque surrogate. The wheel motion, material removal rate, and wheel surface wear were studied via high-speed camera imaging and laser confocal microscopy. The grinding wheel with 80,000 rpm rotational speed had an orbital speed of 14,300 rpm around the 1.5 mm diameter plaque surrogate lumen. After grinding for 120 s, the plaque surrogate inner diameter was enlarged to 3.03 mm, and no wear or loss of diamond abrasive was observed on the grinding wheel. This study demonstrated that the proposed electroplating process for fabricating miniature grinding wheels could effectively remove the calcified plaque surrogate. This research could lead to a more effective and safer atherectomy device with sub-mm miniature diamond wheels to treat lesions deep in coronary and peripheral arteries.