Wearables for health monitoring are rapidly advancing as evidenced by the number of wearable products on the market. More recently, the US Food and Drug Administration approved the Apple Watch for heart monitoring, indicating that wearables are going to be a part of our lives sooner than expected. However, wearables are still based on rigid, conventional electronic materials and fabrication procedures. The use of flexible conducting materials fabricated on flexible substrates allows for more comprehensive health monitoring because of the seamless integration and conformability of such devices with the human skin. Many materials can be used to fabricate flexible electronics such as thin metals, liquid metals, conducting polymers, and 1D and 2D materials. Ti3C2 MXene is a promising 2D material that shows flexibility as well as desirable electronic properties. Ti3C2 MXene is easily processable in aqueous solutions and can be an excellent functional ink for inkjet printing. Here we report the fabrication and the properties of Ti3C2 MXene films inkjet-printed from aqueous dispersions with a nonionic surfactant. The films are uniform and formed with only a few layers on glass and tattoo paper. The MXene films printed on tattoo are used to record ECG signals with comparable signal-to-noise ratio to commercial Ag/AgCl electrodes despite the absence of gels to lower skin-contact impedance. Due to their high charge storage capacity and mixed (ionic and electronic) conductivity, inkjet-printed MXene films open up a new avenue for applications beyond health monitoring.

This research project has investigated the light fastness of ink jet and electrophotographic printed materials by the means of an extensive accelerated and natural ageing test programme. The effect of visible radiation of different wavebands on the deterioration of a selection of ink jet printed materials has also been assessed. The findings of the research indicate that all of the ink jet printed materials tested are sensitive to light and should not therefore, be put on permanent display. Most of the ink jet printed samples exhibited greater light sensitivity to the shorter wavelengths of the visible spectrum, than the longer wavelengths, with damage decreasing as wavelength increases. This relationship was not evident with the cyan and blue printed samples, which showed that their light sensitivity was determined by the spectral absorption characteristics of the printed patch. Some of the ink jet printed materials produced erratic fading rates on exposure to light. This phenomenon was attributed to either the occurrence of photochromism or the disintegration of the dye particles in the ink, but further testing needs to be conducted to gain a better understanding of this reaction. Other factors also influenced the light fastness of the ink jet materials, such as the type of paper employed for printing, ink concentration and ink combination. The electrophotographic printed materials were found to be more stable to light, although the yellow toner from some of the systems would show noticeable fading after approximately 65 to 325 years on permanent display (at 50 lux for eight hours per day). A range of basic conservation treatments was also been investigated and the results indicated that ink jet print materials are very sensitive to all forms of aqueous treatments. Finally, thermal/dark ageing has been performed on the digital printed papers employed in this investigation. The conclusion is that all of the papers are prone to yellowing in storage.

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3D printing has revolutionised traditional manufacturing methods, opening up and distributing design and production of low cost, custom objects to virtually anyone. Tailoring of print material and part geometry allows for the benefits of this technology to reach multiple engineering and scientific fields, given appropriate design. A multidisciplinary approach concerning development of new print materials and methods was undertaken with the aim of further expansion and application of 3D printing towards electrochemical applications. Specific requirements of materials used in this domain, such as conductivity and chemical stability, led to development of functional printable carbon composites, compatible with consumer grade 3D printers. This allows facile production of cheap, reusable, disposable, electrodes for analytical applications, demonstrating heavy metal detection in aqueous media and allowing further tailoring to specific applications to be easily implemented. A new method for printing of cellulose solutions was developed, with post processing of printed parts resulting in biocompatible, porous, conductive structures. When used as electrodes in microbial fuel cells, improved power and current output over traditionally used carbon cloth electrodes was achieved. Other developments resulting from this work applicable to other fields include a novel trajectory generation method based on exponential functions which can be applied to practically any robotic system, as well as improvements to the production process of metal alloy filaments for 3D printing of metallic components.

Bioprinting, defined as depositing cells, extracellular matrices and other biologically relevant materials in user-defined patterns to build tissue constructs de novo or to build upon pre-fabricated scaffolds, is among one of the most promising techniques in tissue engineering. Among the various technologies used for Bioprinting, pressure driven systems are most conducive to preserving cell viability. Herein, we explore the abilities of a novel bioprinter - Digilab, Inc.'s prototype cell printer. The prototype cell printer (Digilab Inc., Holliston, MA) is an automated liquid handling device capable of delivering cell suspension in user-defined patterns onto standard cell culture substrates or custom-designed scaffolds. In this work, the feasibility of using the cell printer to deliver cell suspensions to biological sutures was explored. Cell therapy using stem cells of various types shows promise to aid healing and regeneration in various ailments, including heart failure. Recent evidence suggests that delivering bone-marrow derived mesenchymal stem cells to the infarcted heart reduces infarct size and improves ventricular performance. Current cell delivery systems, however, have critical limitations such as inefficient cell retention, poor survival, and lack of targeted localization. Our laboratories have developed a method to produce discrete fibrin microthreads that can be bundled to form a suture and attached to a needle. These sutures can then be seeded with bone-marrow derived mesenchymal stem cells to deliver these cells to a precise location within the heart wall, both in terms of depth and surface localization. The efficiency of the process of seeding cells onto fibrin thread bundles (sutures) has previously been shown to be 11.8 ± 3.9 %, suggesting that 88% of the cells in suspension are not used. Considering that the proposed cell-therapy model for treatment of myocardial infarction contemplates use of autologous bone-marrow derived stem cells, an improvement in the efficiency of seeding cells onto the fibrin sutures is highly desirable. The feasibility of using Digilab's prototype cell printer to deliver concentrated cell suspension containing human mesenchymal stem cells (hMSCs) directly onto a fibrin thread bundle was explored in this work, in order to determine if this technology could be adapted to seed cells onto such biological sutures. First the effect of the printing process on the viability of hMSCs was assessed by comparing to cells dispensed manually using a hand-held pipette. The viability of hMSCs 24 hours post-dispensing using the cell printer was found to be 90.9 ± 4.0 % and by manual pipetting was 90.6 ± 8.2 % (p = ns). Thereafter a special bioreactor assembly composed of sterilizable Delrin plastic and stainless steel pins was designed to mount fibrin thread bundles onto the deck of the cell printer, to deliver a suspension containing hMSCs on the bundles. Highly targeted delivery of cell suspension directly onto fibrin thread bundles (average diameter 310 µm) was achieved with the bundle suspended in mid-air horizontally parallel to the printer's deck mounted on the bioreactor assembly. To compare seeding efficiency, fibrin thread bundles were simultaneously seeded with hMSCs using either the cell printer or the current method (tube-rotator method) and incubated for 24 hours. Seeded thread bundles were visualized using confocal microscopy and the number of cells per unit length of the bundle was determined for each group. The average seeding efficiency with the tube rotator method was 7.0 ± 0.03 % while the cell printer was 3.46 ± 2.24% (p = ns). In conclusion, the cell printer was found to handle cells as gently as manual pipetting, preserve their viability, with the added abilities to dispense cells in user-defined patterns in an automated manner. With further development, such as localized temperature, gas and humidity control on the cell printer's deck to aid cell survival, the seeding efficiency is likely to improve. The feasibility of using this automated liquid handling technology to deliver cells to biological scaffolds in specified patterns to develop vehicles for cell therapy was shown in this study. Seeding other cell types on other scaffolds along with selectively loading them with growth factors or multiple cell types can also be considered. In sum, the cell printer shows considerable potential to develop novel vehicles for cell therapy. It empowers researchers with a supervision-free, gentle, patterned cell dispensing technique while preserving cell viability and a sterile environment. Looking forward, de novo biofabrication of tissue replicates on a small scale using the cell printer to dispense cells, extracellular matrices, and growth factors in different combinations is a very realistic possibility.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING / Includes bibliographical references. / by Kenneth James Dreshfield. / M.S.

A 3D-printed microfluidic lab-on-a-disc (LOAD) device was designed and manufactured using a low cost ( ̃£1600) consumer grade fused deposition modelling (FDM) Ultimaker 2+ 3D printer with imbedded microfluidic channels 1 mm wide, 400 μm depth and with a volumetric capacity of approximate 23 μl. FDM printers are not typically used, or are capable, of producing the fine detailed structures required for microfluidic fabrication; in addition 3D-printed objects can suffer from poor optical transparency. However, in this work, imbedded microfluidic channels were produced and the optical transparency of the device was improved though manufacture optimisation to such a point that optical colourimetric assays can be performed in a microfluidic cuvette device with sample path length of 500 μm and volumetric capacity of 190 μl. When acetone vapour treatment was used, it was possible to improve transparency of plastic samples by up to a further 30%. The LOAD device is capable of being spun using an unmodified optical disc drive (ODD), demonstrating the centrifugation based separation of plasma from whole blood in a low-cost FDM 3D-printed microfluidic LOAD device. A cholesterol assay and glucose assay was developed and optimised using cholesterol oxidase (ChOx) or glucose oxidase (GlOx) respectively and horseradish peroxidase (HRP) for the oxidative coupling of chromotropic acid (CTA) and 4-aminoantipyrine (AAP). This produced a blue quinoneimine dye with a broad absorbance peaking at 590 nm for the quantification of cholesterol/glucose in solution. The colourimetric enzymatic cascade assays were developed for use within low-cost FDM 3D-printed microfluidic devices to demonstrate the capabilities and functionality of the devices. For comparison, the assay was run in standard 96 well plates with a commercial plate reader. The results demonstrated that the quantification of 0-10 mM glucose solution using a 3D-printed microfluidic optical device had a performance comparable to a plate reader assay; glucose assay in whole blood samples R2 = 0.96.

Communication trough documents have become a key element in every company?s life, communication channels expanded to include not just print but fax, web and email. Marketing and market studies repeatedly show that personalized documents (delivered through these channels) can positively influence customer relationship hereby help to achieve business success. For IT companies these changes created an exciting new opportunity to develop new solutions and offer new services. There are several companies on the market of personalized document creation which offering high quality product and services. Therefore it might not be easy to make the right choice, to find the most fitting solution and the best vendor. The main objective of this thesis is to provide detailed information about personalized document creation in general and to introduce the market leading vendors and their technology.

This thesis provided the foundational work for a low-cost three-dimensional (3D) printed custom knee brace. Specifically, the objective was to research, develop and implement a novel workflow aimed to be easy to use and available to anyone who has access to a smartphone camera and 3D printing services. The developed workflow was used to manufacture two prototypes which proved valuable in the design iterations. As a result, an improved hinge was designed which has increased mechanical strength. Additionally, a smartphone photogrammetry validation study was included which provided preliminary results on the accuracy and precision. This novel measurement method has the potential to require little training and could be disseminated through video instructions posted online. The intention is to enable the patient to collect their own “3D scan” with the help of a friend or family member, effectively removing the need to book an appointment simply for collecting custom measurements. Lastly, it would allow the clinician to focus all their time on clinically relevant design tasks such as checking alignment, fit and comfort, which could all potentially be improved by adopting such digital methods. The ultimate vision for this work is to enable manufacturing of better custom knee braces at a reduce cost which are easily accessible for low-income populations.

abstract: This dissertation focuses on the corpus of Zang Maoxun’s literary creations in The Collection from the Fubao Hall and investigates his involvement in the cultural activities of the Jinling Poetry Society. Unearthing how Zang and this Society, as self and community, played an instrumental role in creating and sustaining a network of dramatists and drama critics in the Jiangnan region, a careful review of his poems and prose shows the extent to which text preparation, commentary, and printing were at the center of his communications with his social circle. Moreover, this dissertation unpacks Zang’s contribution to the promotion of dramatic texts through a thorough examination of his ardent editorial work in revising Tang Xianzu’s The Four Dream Plays from the Jade Tea Hall, the epitome of the southern musical drama. By using Zang’s 1618 Diaochong guan edition of his adaptations as a focal point, this dissertation compares it with three late Ming editions of Tang’s plays printed in the dual colors of red-and-black ink. In light of their innovative editorial designs, and the varying evaluations formed in their pages about Zang’s editorial work, this dissertation reveals the importance of Zang’s adaptations in the history of The Four Dream Plays’ textual transmission, as well as the interplay between the tradition of drama criticism and the new technology of multicolor printing and consequent innovation in editorial principles. / Dissertation/Thesis / Doctoral Dissertation East Asian Languages and Civilizations 2019