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Laser powder bed fusion (LPBF) enables the fabrication of intricate, geometrically complex structures with a sufficiently fine surface finish for many engineering applications with a diversity of available feedstock metals. However, the production rate of LPBF systems is not well suited for mass production in comparison to traditional manufacturing methods. LPBF systems measure their deposition rates in 100's of grams per hour, while other processes measure in kilograms per hour or even in the case of processes such as forming, stamping, and casting, 100's of kilograms per hour. To be widely adopted in industry for mass production, LPBF requires a new scalable architecture that enables many orders of magnitude improvement in deposition rate, while maintaining the geometry freedom of additive manufacturing. This article explores concepts that could achieve as much as four orders of magnitude increase in the production rate through the application of (1) rotary table kinematic arrangements; (2) a dramatic number of simultaneously operating lasers; (3) reductions of laser optic size; (4) improved scanning techniques; and (5) an optimization of toroidal build plate size. To theoretically demonstrate the possibilities of production improvements, a productivity analysis is proposed for synchronous reluctance motors with relevance to the electric vehicle industry, given the recent increase in the diversity of printable soft magnetic alloys. The analysis provides insights into the impact of the architecture and process parameters necessary to optimize rotary powder bed fusion for mass production.
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Additive manufacturing is catalyzing a new class of volumetrically varying lattice structures in which the dynamic mechanical response can be tailored for a specific application. Simultaneously, a diversity of materials is now available as feedstock including elastomers, which provide high viscoelasticity and increased durability. The combined benefits of complex lattices coupled with elastomers is particularly appealing for anatomy-specific wearable applications such as in athletic or safety equipment. In this study, Siemens' DARPA TRADES-funded design and geometry-generation software, Mithril, was leveraged to design vertically-graded and uniform lattices, the configurations of which offer varying degrees of stiffness. The designed lattices were fabricated in two elastomers using different additive manufacturing processes: (a) vat photopolymerization (with compliant SIL30 elastomer from Carbon) and (b) thermoplastic material extrusion (with Ultimaker™ TPU filament providing increased stiffness). Both materials provided unique benefits with the SIL30 material offering compliance suitable for lower energy impacts and the Ultimaker™ TPU offering improved protection against higher impact energies. Moreover, a hybrid lattice combination of both materials was evaluated and demonstrated the simultaneous benefits of each, with good performance across a wider range of impact energies. This study explores the design, material, and process space for manufacturing a new class of comfortable, energy-absorbing protective equipment to protect athletes, consumers, soldiers, first responders, and packaged goods.
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The aim of this study was to investigate the association between socioeconomic status and erectile dysfunction. Data were obtained from the National Health and Nutrition Examination Survey, a nationally representative survey of the United States population. Socioeconomic status was estimated using the poverty income ratio, a ratio of family income to established poverty levels. Erectile function was assessed from a single survey question and was divided into two groups: normal (always and usually able to maintain an erection) and erectile dysfunction (sometimes or never able to maintain an erection). Multivariable logistic regression, using a multi-model approach, was used to characterize the interplay between well-established risk factors for erectile dysfunction and socioeconomic status. Our final cohort included 3679 respondents, representative of 81,255,155 subjects with a mean age of 44.4 [SE, 0.365]. Multivariable logistic regression showed that low-income respondents were significantly more likely to report erectile dysfunction [adjusted odds ratio (AOR) = 1.95, 95% CI 1.28-2.96; p = 0.003] compared to higher-income respondents. This study suggests that low socioeconomic status may be associated with erectile dysfunction in a large, nationally representative sample.
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Disfunção Erétil , Masculino , Humanos , Estados Unidos/epidemiologia , Adulto , Disfunção Erétil/complicações , Disfunção Erétil/epidemiologia , Inquéritos Nutricionais , Classe Social , Fatores de Risco , Inquéritos e Questionários , Fatores SocioeconômicosRESUMO
Additive manufacturing technologies have facilitated the construction of intricate geometries, which otherwise would be an extenuating task to accomplish by using traditional processes. Particularly, this work addresses the manufacturing, testing, and modeling of thermoplastic polyurethane (TPU) lattices. Here, a discussion of different unit cells found in the literature is presented, along with the based materials used by other authors and the tests performed in diverse studies, from which a necessity to improve the dynamic modeling of polymeric lattices was identified. This research focused on the experimental and numerical analysis of elastomeric lattices under quasi-static and dynamic compressive loads, using a Kelvin unit cell to design and build non-graded and spatially side-graded lattices. The base material behavior was fitted to an Ogden 3rd-order hyperelastic material model and used as input for the numerical work through finite element analysis (FEA). The quasi-static and impact loading FEA results from the lattices showed a good agreement with the experimental data, and by using the validated simulation methodology, additional special cases were simulated and compared. Finally, the information extracted from FEA allowed for a comparison of the performance of the lattice configurations considered herein.
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Additive manufacturing, also called 3D printing, has the potential to enable the development of flexible, wearable and customizable batteries of any shape, maximizing energy storage while also reducing dead-weight and volume. In this work, for the first time, three-dimensional complex electrode structures of high-energy density LiNi1/3Mn1/3Co1/3O2 (NMC 111) material are developed by means of a vat photopolymerization (VPP) process combined with an innovative precursor approach. This innovative approach involves the solubilization of metal precursor salts into a UV-photopolymerizable resin, so that detrimental light scattering and increased viscosity are minimized, followed by the in-situ synthesis of NMC 111 during thermal post-processing of the printed item. The absence of solid particles within the initial resin allows the production of smaller printed features that are crucial for 3D battery design. The formulation of the UV-photopolymerizable composite resin and 3D printing of complex structures, followed by an optimization of the thermal post-processing yielding NMC 111 is thoroughly described in this study. Based on these results, this work addresses one of the key aspects for 3D printed batteries via a precursor approach: the need for a compromise between electrochemical and mechanical performance in order to obtain fully functional 3D printed electrodes. In addition, it discusses the gaps that limit the multi-material 3D printing of batteries via the VPP process.
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PURPOSE: This study aimed to investigate the relationship between self-reported food security and kidney stone formation. METHODS: Data were collected from the National Health and Nutrition Examination Survey (NHANES), a database representative of the United States population. Food security status was assessed using the US Household Food Security Survey Module: Six-Item Short Form. Characteristics of patients were compared using the Chi-square test and the student t-test. Multivariate logistic regression was performed using a multi-model approach. RESULTS: We analyzed 6,800 NHANES survey respondents. 37.2% of respondents were categorized as having "low food security" (scores 2-4) and 24.0% having "very low food security" (scores 5-6). 8.4% of respondents had a history of kidney stones. We found that people with very low food security had a 42% increased likelihood of developing kidney stones compared to those with high or marginal food security, after controlling for race, age, and comorbidities (OR 1.42; 95% CI 1.01-1.99). Between the different food security groups, no significant differences were observed in age, race/ethnicity, body mass index, gout history, osteoporosis history, or coronary artery disease history. Lower food security was associated with slightly younger age (< 1 year difference, p = 0.001), higher poverty-income ratio (p = 0.001), and many comorbidities, including kidney stones (p = 0.007). CONCLUSION: Our study provides evidence for an association between food access and the risk of kidney stone disease. Given these findings, food insecurity should be investigated as a modifiable risk factor for the development of kidney stone disease.
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Abastecimento de Alimentos , Cálculos Renais , Humanos , Estados Unidos/epidemiologia , Inquéritos Nutricionais , Pobreza , Insegurança Alimentar , Cálculos Renais/epidemiologiaRESUMO
OBJECTIVES: To determine if race/ethnicity impacts disclosure of erectile function. METHODS: Data on age, education, erectile function, and past medical history were obtained from the National Health and Nutrition Examination Survey. Response rates to a single survey question regarding erectile function were calculated and compared between race/ethnicity groups. Two subgroups were created by excluding non-responders to questions about hypertension and prostate disease to control for overall non-responsiveness and urologic health literacy. RESULTS: Our final cohort consisted of 4,694 men. Overall, 3,898 (83.0%) responded to the erectile function survey question. Race/ethnicity was a significant factor in overall response rates to the Erectile function question: 85.2% in non-hispanic white, 82.3% in non-hispanic black, 81.2% in hispanic, and 64.8% in other subjects (P<.001). Race/ethnicity remained significantly associated with responses rates among both subgroups. Multivariate logistic regression using the prostate disease subgroup showed that non-hispanic black (AOR = 2.02, 95% CI 1.01-4.03, P = .047) and hispanic (AOR = 2.18, 95% CI 1.19-4.00, P = .012) participants were significantly more likely to not disclose their erectile function compared to non-hispanic white participants after controlling for age and education. CONCLUSION: Non-hispanic black and hispanic men were significantly less likely to disclose their erectile function than non-hispanic white men in an anonymous, nationally representative survey. A better understanding of how cultural differences affect reporting of erectile function is important in improving patient care and accurately studying outcomes of urological procedures.
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Disfunção Erétil , Etnicidade , Revelação , Humanos , Masculino , Inquéritos Nutricionais , Grupos RaciaisRESUMO
OBJECTIVE: To analyze Twitter engagement in response to the urology match during the COVID-19 pandemic. METHODS: Tweets containing the hashtags "#uromatch" or "#AUAmatch" during the 2021 and 2022 Match Week were reviewed. Date, author type and number of followers, general content, and engagement with each Tweet was collected. Differences in engagement between author type and content were analyzed using the Kruskal-Wallis H test. Tweet characteristics were compared between the 2021 and 2022 Match Cycles using the Chi-Square test. RESULTS: There were 656 Tweets in total, with 272 (43.5%) from 2021 and 353 (56.5%) from 2022. Medical students' and residency programs' posts received significantly more Tweet engagement than those by residents/fellows, attendings, or the AUA (P <.05). Tweets focusing on announcing a new residency class and personal announcements of match results received significantly more engagements than other content categories (P <.05). In 2022, there was a significantly higher percentage of Tweets about advice for unmatched applicants (2.2 vs 12.5; P <.001), match statistics (0.4 vs 2.9; P = .028) and focus on underrepresented groups in urology (0.7 vs 3.4; P = .029). CONCLUSION: The Twitter response to the urology match between 2021 and 2022 mirrored the increase in competitiveness, with greater participation and an increasing focus on the difficulty of matching. During Match Week, Twitter is a readily available source of information for programs, matched students, and unmatched students alike. As we continue to embrace virtual platforms, we believe that Twitter will remain a major source of match-related information and can be an instrumental tool for broader networking in our field.
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COVID-19 , Internato e Residência , Mídias Sociais , Urologia , COVID-19/epidemiologia , Humanos , PandemiasRESUMO
OBJECTIVE: To perform a systematic review of mixed epithelial stromal tumor of the seminal vesicle (SV) to characterize the diagnosis and treatment of this rare condition. METHODS: "Seminal vesicle mixed epithelial stromal tumor" OR "seminal vesicle cystadenoma" were searched on PubMed/MEDLINE for relevant articles through 6 September 2021. Articles were eligible if they were in English, accessible via our university library services, and if the abstract was concordant with the content of the publication. Reference lists of included articles were reviewed to identify additional relevant articles. RESULTS: In total, 66 articles were identified, of which 34 (N = 36 patients) were included. The most common presenting symptoms were lower urinary tract symptoms (33%, 12/36), dysuria (22%, 8/36), lower abdominal pain (17%, 6/36), and hematuria (17%, 6/36). However, there were eight cases (23%, 8/36) of asymptomatic incidental SV tumors. A biopsy was performed in 47% of cases (17/36), of which 53% (9/17) showed benign findings, 29% (5/17) were inconclusive, and 18% (3/17) SV cystadenoma. Surgical resection was performed using open (57%, 20/35), laparoscopic (26%, 9/35), or robotic (17%, 6/35) techniques. The majority (94%, 34/36) of the SV tumors were low-grade. Long-term follow-up was reported for 15 patients in which two patients (13%, 2/15) had tumor recurrence. CONCLUSION: High rate of inconclusive biopsy of SV tumors suggests that routine biopsy is of questionable utility. Surgical excision frequently relieves symptoms and confirms accurate pathologic diagnosis. After tumor removal, patients should be surveilled with cross-sectional imaging of the pelvis given the possibility of tumor recurrence.
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Cistadenoma , Neoplasias dos Genitais Masculinos , Cistadenoma/diagnóstico , Cistadenoma/cirurgia , Neoplasias dos Genitais Masculinos/diagnóstico , Neoplasias dos Genitais Masculinos/cirurgia , Humanos , Masculino , Recidiva Local de Neoplasia/patologia , Pelve/patologia , Glândulas Seminais/patologia , Glândulas Seminais/cirurgiaRESUMO
Interstitial cystitis/bladder pain syndrome (IC/BPS) is a disorder characterized by bladder pain upon filling which severely affects quality of life. Clinical presentation can vary. Local inflammatory events typify the clinical presentation of IC/BPS patients with Hunner lesions (IC/BPS-HL). It has previously been proposed that B cells are more prevalent in HL, but understanding their exact role in this environment requires a more complete immunological profile of HL. We characterized immunological dysfunction specifically in HL using immunohistochemistry. We detected significantly more plasma cells (50× increase, p < 0.0001), B cells (28× increase, p < 0.0001), T cells (3× increase, p < 0.0001), monocytes/macrophages (6× increase, p < 0.0001), granulocytes (4× increase, p < 0.0001), and natural killer cells (2× increase, p = 0.0249) in IC/BPS patients with HL than in unaffected controls (UC). Patients with IC/BPS-HL also had significantly elevated urinary levels of IL-6 (p = 0.0054), TNF-α (p = 0.0064) and IL-13 (p = 0.0304) compared to patients with IC/BPS without HL (IC/BPS-NHL). In contrast, IL-12p70 levels were significantly lower in the patients with HL than in those without these lesions (p = 0.0422). Different cytokines were elevated in the urine of IC/BPS patients with and without HL, indicating that different disease processes are active in IC/BPS patients with and without HL. Elevated levels of CD138+, CD20+, and CD3+ cells in HL are consistent B and T-cell involvement in disease processes within HL.
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Cistite Intersticial , Cistite Intersticial/patologia , Cistite Intersticial/urina , Citocinas , Humanos , Qualidade de VidaRESUMO
OBJECTIVE: To analyze the National Hospital Ambulatory Medical Care Survey (NHAMCS) database to determine geographic and temporal trends, as well as variables associated with the likelihood of receiving an opioid prescription for urolithiasis in United States (US) emergency departments (EDs). MATERIALS AND METHODS: All ED visits for urolithiasis between 2006 and 2018 in the NHAMCS database were analyzed. Age, race/ethnicity, insurance status, ED provider credentials, geographic region, and urban vs rural hospital status were extracted. Linear regression was used to examine overall/regional trends in opioid prescriptions over time. Logistic regression was used to estimate factors associated with higher odds of receiving opioids. RESULTS: Fourteen million visits were analyzed, of which, 79.1% (11.0 million) received an opioid prescription. From 2014 to 2018 there was a decline of 3.65%/year of the proportion of visits receiving an opioid prescription (R2â¯=â¯0.86, Pâ¯=â¯.008). Non-Hispanic Black race was associated with a lower chance of receiving opioid prescription (ORâ¯=â¯0.57, Pâ¯=â¯.02) compared to Non-Hispanic Whites (NHW). Midwestern hospitals had higher odds of opioid prescription compared to the Northeast (ORâ¯=â¯2.05, Pâ¯=â¯.006). Rural hospitals had lower odds of opioid prescription compared to urban hospitals (ORâ¯=â¯0.62, Pâ¯=â¯.02). CONCLUSION: Opioid prescriptions for patients presenting with urolithiasis to the ED have steadily declined from 2014 to 2018, except in the Midwest. NHW race, Midwest region, and urban EDs increase the likelihood of receiving opioids. Continued efforts encouraging non-opioid alternatives for urolithiasis are essential, specifically in Midwestern EDs, to mitigate the ongoing opioid epidemic in the US.
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Analgesia , Alcaloides Opiáceos , Urolitíase , Analgésicos Opioides/uso terapêutico , Serviço Hospitalar de Emergência , Pesquisas sobre Atenção à Saúde , Hospitais , Humanos , Dor , Padrões de Prática Médica , Prescrições , Estados Unidos , Urolitíase/tratamento farmacológicoRESUMO
OBJECTIVES: We investigated the impact of anemia based on admission hemoglobin (Hb) level as a prognostic risk factor for severe outcomes in hospitalized patients with coronavirus disease 2019 (COVID-19). METHODS: A single-center, retrospective cohort study was conducted from a random sample of 733 adult patients (age ≥ 18 years) obtained from a total of 4356 laboratory confirmed SARS-CoV-2 cases who presented to the Emergency Department of Montefiore Medical Center between March-June 2020. The primary outcome was a composite endpoint of in-hospital severe outcomes of COVID-19. A secondary outcome was in-hospital all-cause mortality. RESULTS: Among the 733 patients included in our final analysis, 438 patients (59.8%) presented with anemia. 105 patients (14.3%) had mild, and 333 patients (45.5%) had moderate-severe anemia. Overall, 437 patients (59.6%) had a composite endpoint of severe outcomes. On-admission anemia was an independent risk factor for all-cause mortality, (Odds Ratio 1.52, 95% CI [1.01-2.30], p = 0.046) but not for composite severe outcomes. However, moderate-severe anemia (Hb < 11 g/dL) on admission was independently associated with both severe outcomes (OR1.53, 95% CI [1.05-2.23], p = 0.028) and mortality (OR 1.67, 95% CI [1.09-2.56], p = 0.019) during hospitalization. CONCLUSION: Anemia on admission was independently associated with increased odds of all-cause mortality in patients hospitalized with COVID-19. Furthermore, moderate-severe anemia (Hb <11 g/dL) was an independent risk factor for severe COVID-19 outcomes. Moving forward, COVID-19 patient management and risk stratification may benefit from addressing anemia on admission.
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Injúria Renal Aguda/epidemiologia , Anemia/sangue , COVID-19/sangue , Mortalidade Hospitalar , Hipotensão/epidemiologia , Insuficiência Respiratória/epidemiologia , Choque Séptico/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Anemia/terapia , Transfusão de Sangue/estatística & dados numéricos , COVID-19/mortalidade , Causas de Morte , Estudos de Coortes , Feminino , Hemoglobinas/metabolismo , Hospitalização , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , SARS-CoV-2 , Índice de Gravidade de DoençaRESUMO
Shape memory polymers (SMPs) are materials capable of changing their structural configuration from a fixed shape to a temporary shape, and vice versa when subjected to a thermal stimulus. The present work has investigated the 3D printing process of a shape memory polymer (SMP)-based polyurethane using a material extrusion technology. Here, SMP pellets were fed into a printing unit, and actuating coupons were manufactured. In contrast to the conventional film-casting manufacturing processes of SMPs, the use of 3D printing allows the production of complex parts for smart electronics and morphing structures. In the present work, the memory performance of the actuating structure was investigated, and their fundamental recovery and mechanical properties were characterized. The preliminary results show that the assembled structures were able to recover their original conformation following a thermal input. The printed parts were also stamped with a QR code on the surface to include an unclonable pattern for addressing counterfeit features. The stamped coupons were subjected to a deformation-recovery shape process, and it was observed that the QR code was recognized after the parts returned to their original shape. The combination of shape memory effect with authentication features allows for a new dimension of counterfeit thwarting. The 3D-printed SMP parts in this work were also combined with shape memory alloys to create a smart actuator to act as a two-way switch to control data collection of a microcontroller.
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Powder bed fusion of polymers is becoming increasingly adopted by a variety of industries to tailor the strength, weight and functionality of end-use products. To meet the high standards of the modern manufacturing industry, parts built with powder bed fusion require consistent properties and to be free of defects, which is intrinsically connected to the quality of the powder bed prior to melting. The hypothesis of this work is that the roughness of the top surface of an unmelted powder bed can serve as a proxy for the powder bed density, which is known to correlate with final part density. In this study, a laser line scan profilometer is integrated onto the recoater arm of a custom powder test bench, which is able to automatically create layers of powder. A diverse group of polymers was investigated including polyamide 12 (PA12), polyamide 11 (PA11), polypropylene (PP), and a thermoplastic elastomer (TPU) under different recoating speed in order to increase the variance of the dataset. Data analytics were employed to compare roughness to measured powder bed density and a statically significant correlation was established between them.
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The production and mechanical properties of fiber metal laminates (FMLs) based on 3D printed composites have been investigated in this study. FMLs are structures constituting an alternating arrangement of metal and composite materials that are used in the aerospace sector due to their unique mechanical performance. 3D printing technology in FMLs could allow the production of structures with customized configuration and performance. A series of continuous carbon fiber reinforced composites were printed on a Markforged system and placed between layers of aluminum alloy to manufacture a novel breed of FMLs in this study. These laminates were subjected to tensile, low velocity and high velocity impact tests. The results show that the tensile strength of the FMLs falls between the strength of their constituent materials, while the low and high velocity impact performance of the FMLs is superior to those observed for the plain aluminum and the composite material. This mechanism is related to the energy absorption process displayed by the plastic deformation, and interfacial delamination within the laminates. The present work expects to provide an initial research platform for considering 3D printing in the manufacturing process of hybrid laminates.
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OBJECTIVES: We report and analyze eight cases in which patients were referred from gastroenterology (GI) to otolaryngology following esophagogastroduodenoscopy (EGD). We aim to provide specific examples of head and neck pathology encountered by gastroenterologists during upper endoscopy. METHODS: A series of eight cases between 2016 and 2019 were analyzed by chart review. In each case, otolaryngology consultation was requested after an abnormality was noticed by a gastroenterologist during EGD. Subsequent laryngoscopy or bronchoscopy was performed in all cases allowing for image comparison. Select images comparing EGD to laryngoscopy findings are included as well as a literature review concerning the nature of communication between the two specialties. RESULTS: Eight adult patients were referred to otolaryngology for abnormalities noted by a gastroenterologist during EGD at the following anatomic sites: soft palate (n=1), base of tongue (n=2), glottis (n=3), and interarytenoid mucosa (n=1). Additionally, a potential airway foreign body was noted on EGD which was ultimately determined to represent normal subglottic anatomy by bronchoscopy. Some 5/8 (63%) cases were considered true pathology while 3/8 (37%) represented normal anatomy or anatomic variants upon subsequent otolaryngologic evaluation. CONCLUSIONS: There is minimal literature regarding the nature of referrals from GI to otolaryngology following EGD. Our findings suggest that EGD offers a unique opportunity for early detection of otolaryngologic pathology. However, certain inter-specialty anatomic knowledge gaps were noted which contributed to occasional unnecessary referrals, procedures, and associated patient anxiety. We hope that the results of this study can inform future research aimed at improving communication and collaboration between the two specialties.
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Layer-by-layer deposition of materials to manufacture parts-better known as three-dimensional (3D) printing or additive manufacturing-has been flourishing as a fabrication process in the past several years and now can create complex geometries for use as models, assembly fixtures, and production molds. Increasing interest has focused on the use of this technology for direct manufacturing of production parts; however, it remains generally limited to single-material fabrication, which can limit the end-use functionality of the fabricated structures. The next generation of 3D printing will entail not only the integration of dissimilar materials but the embedding of active components in order to deliver functionality that was not possible previously. Examples could include arbitrarily shaped electronics with integrated microfluidic thermal management and intelligent prostheses custom-fit to the anatomy of a specific patient. We review the state of the art in multiprocess (or hybrid) 3D printing, in which complementary processes, both novel and traditional, are combined to advance the future of manufacturing.
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Conductive inks are key enablers for the use of printing techniques in the fabrication of electronic systems. Focus on the understanding of aspects controlling the electrical performance of conductive ink is paramount. A comparison was made between microparticle Ag inks and an Ag nanoparticle ink. The microstructures resulting from thermal cure processes were characterized morphologically and also in terms of their effect on the resistivity of printed traces. For microparticle inks, the variability of resistivity measurements between samples as defined by coefficient of variation (CV) was greater than 0.1 when the resistivity was 10 to 50 times that of bulk Ag. When the resistivity was lower (~1.4 times that of bulk Ag) the CV of sample sets was less than 0.1. In the case of the nanoparticle ink, resistivity was found to decrease by a factor ranging from 1.2 to 1.5 after doubling the amount of layers printed prior to curing though it was expected to remain the same. Increasing the amount of layers printed also enhanced the sintering process.