Thermally triggered nanorocket from double-walled carbon nanotube in water

In this work, we propose and investigate the use of double-walled carbon nanotubes (DWCNTs) as nanosized rockets. The nanotubes are immersed in water, and the propulsion of inner nanotube is achieved by heating the water encapsulated within the DWCNT. Considering a setup made of (5,5)(8,8) DWCNT, molecular dynamics simulations for different water temperatures show that the trajectory can be divided into four phases: trigger, expulsion, damping and final equilibrium. After analysing the dynamics and the involved forces, we find out that the inner nanotube expulsion is mainly controlled by van der Waals interactions between the nanotubes; whereas, the damping role is predominantly played by the external aqueous environment. Based on these results, we propose an analytical model able to predict both the triggering time for a given water temperature and the whole dynamics of nanorocket. The validity of such dynamical model can be extended also to a broader variety of DWCNT configurations, once the different forces acting on the inner nanotube are provided. The proposed model may contribute to assist the design of nanorockets in several nanotechnology applications, such as triggered drug delivery, cell membrane piercing, or colloids with thermophoretic properties

I-support soft arm for assistance tasks: a new manufacturing approach based on 3D printing and characterization

AbstractSoft robotics is an emerging scientific field well known for being widespread employed in several applications where dexterity and safe interaction are of major importance. In particular, a very challenging scenario in which it is involved concerns bio-medical field. In the last few years, several soft robotic devices have been developed to assist elderly people in daily tasks. In this paper, the authors present a new manufacturing approach for the fabrication of I-SUPPORT, a soft arm used to help needful people during shower activities. The proposed I-SUPPORT version, based on pneumatic and cable-driven actuation, is manufactured using Fused Filament Fabrication (FFF), the most common and inexpensive Additive Manufacturing (AM) technology. The advantages offered by FFF technology compared to traditional manufacturing methods regard: (i) the possibility to increase the automation degree of the process by reducing manual tasks, (ii) the decrease of assembly operations and (iii) an improvement in terms of supply chain. Moreover, the constitutive I-SUPPORT elements have been printed separately to save time, reduce materials and optimize the waste in case of failure. Afterwards, the proposed soft robotic arm has been tested to evaluate the performances and of the chambers, module and the whole I-SUPPORT manipulator

Entwicklung und Automatisierung 3D-gedruckter mikrofluidischer Systeme zur Integration und Kultivierung adhärenter Zellkulturen

Mikrofluidische Systeme werden zur Manipulation von Flüssigkeiten auf Mikroebene eingesetzt. Von ihnen profitieren insbesondere Biowissenschaften durch die Reduktion von Reagenzien und die Automatisierung ganzer Arbeitsabläufe. Die Mikrostrukturierung erlaubt zudem die Entwicklung neuartiger mikrofluidischer Zellkultursysteme wie den organ-on-a-chip Systemen. Diese Systeme zeichnen sich durch eine höhere physiologische Relevanz gegenüber klassischen in vitro Systemen aus und können zur Rekonstruktion einzelner Organfunktionen genutzt werden. Aufgrund ihrer komplizierten Fertigung wird jedoch der Zugang zu diesen Systemen für Biowissenschaftler:innen er-schwert, sodass ihr Potential noch kaum in kommerziellen Produkten realisiert werden konnte. Eine Lösung bietet die additive Fertigung (3D-Druck) mikrofluidischer Systeme, durch die die unkomplizierte Herstellung eigener Prototypen an Ort und Stelle ermöglicht wird. Um den 3D-Druck jedoch auch für die Herstellung mikrofluidischer Zellkultursysteme nutzen zu können, benötigt es deutlich mehr Biokompatibilitätsstudien zu neuen 3D-Druckmaterialien. In diesem Sinne wurde in dem ersten Teil dieser Arbeit die in vitro Biokompatibilität eines aus Polyacrylat bestehenden, hitzebeständigen 3D-Druckmaterials sowie dessen Eignung für die Heißdampfsterilisation untersucht. Dabei konnte eine Biokompatibilität gegenüber adhärenten Mausfibroblasten und Hefezellen nachgewiesen werden. Diese Ergebnis-se ermöglichen somit den Einsatz des Materials für die Zellkultur. Die Biokompatibilität blieb auch nach Heißdampfsteri-lisation unbeeinträchtigt, sodass mit diesem Material gedruckte Zellkultursysteme unkompliziert sterilisiert werden können. Im Gegensatz dazu erwies sich das Material für menschliche embryonale Nierenzellen in Suspension als schädlich, was die Bedeutung einer auf den Organismus und die Anwendung zugeschnittenen Biokompatibilitätsprü-fung verdeutlicht. Im zweiten Teil dieser Arbeit wurde das evaluierte 3D-Druckmaterial zur Herstellung eines vollautomatischen mikroflui-dischen Ventilsystems eingesetzt, dessen Nutzen anschließend durch die Automatisierung eines Zellkulturassays als Machbarkeitsstudie demonstriert wurde. Alle mikrofluidischen Komponenten inklusive Anschlüsse, Mikromischer, Mikroventile und Auslässe wurden dabei in einem Stück gefertigt. Die kostengünstige und leicht zu steuernde Aktuation der 3D-gedruckten Ventilmembranen durch Servomotoren ist ein komplett neuer Ansatz. Die Automatisierung des Sys-tems erfolgte durch einen Raspberry Pi Computer sowie selbst entwickelter Python Skripte. Durch den kompakten Com-puter wird die portable und ferngesteuerte Verwendung des Ventilsystems ermöglicht. Nachdem eine zuverlässige Mischgenauigkeit sowie die hohe Robustheit der Ventile gezeigt werden konnte, wurde das mikrofluidische Ventilsys-tem zur Automatisierung eines Zytotoxizitätsassays als Machbarkeitsstudie verwendet. Das von der Konzentration des Toxins abhängige Zellwachstum wurde dabei mittels Lebendzellmikroskopie und Bildverarbeitung automatisiert ausge-wertet. Die Ergebnisse wurden anschließend mit denen eines pipettierten Assays verglichen. Beide Assays zeigten ein fast identisches Wachstumsverhalten, das die Eignung des Systems für die Zellkultur beweist. Letztendlich konnte durch den 3D-Druck in Kombination mit der Biokompatibilitätsbestimmung eines 3D-Druckmaterials die Automatisierung von Zellkulturassays durch ein neu entwickeltes, 3D-gedrucktes mikrofluidisches Ventilsystem ermöglicht werden. Mit der Veröffentlichung der 3D-Modelle und Skripte ist es Wissenschaftler:innen nun möglich, das System an ihre eigenen Anwendungen anzupassen.Deutsche Forschungsgemeinschaft/Emmy Noether/346772917/E

DEVELOPMENT OF FUNCTIONAL NANOCOMPOSITE MATERIALS TOWARDS BIODEGRADABLE SOFT ROBOTICS AND FLEXIBLE ELECTRONICS

World population is continuously growing, as well as the influence we have on the ecosystem\u2019s natural equilibrium. Moreover, such growth is not homogeneous and it results in an overall increase of older people. Humanity\u2019s activity, growth and aging leads to many challenging issues to address: among them, there are the spread of suddenly and/or chronic diseases, malnutrition, resource pressure and environmental pollution. Research in the novel field of biodegradable soft robotics and electronics can help dealing with these issues. In fact, to face the aging of the population, it is necessary an improvement in rehabilitation technologies, physiological and continuous monitoring, as well as personalized care and therapy. Also in the agricultural sector, an accurate and efficient direct measure of the plants health conditions would be of help especially in the less-developed countries. But since living beings, such as humans and plants, are constituted by soft tissues that continuously change their size and shapes, today\u2019s traditional technologies, based on rigid materials, may not be able to provide an efficient interaction necessary to satisfy these needs: the mechanical mismatch is too prohibitive. Instead, soft robotic systems and devices can be designed to combine active functionalities with soft mechanical properties that can allow them to efficiently and safely interact with soft living tissues. Soft implantable biomedical devices, smart rehabilitation devices and compliant sensors for plants are all applications that can be achieved with soft technologies. The development of sophisticated autonomous soft systems needs the integration on a unique soft body or platform of many functionalities (such as mechanical actuation, energy harvesting, storage and delivery, sensing capabilities). A great research interest is recently arising on this topic, but yet not so many groups are focusing their efforts in the use of natural-derived and biodegradable raw materials. In fact, resource pressure and environmental pollution are becoming more and more critical problems. It should be completely avoided the use of in exhaustion, pollutant, toxic and non-degradable resources, such as lithium, petroleum derivatives, halogenated compounds and organic solvents. So-obtained biodegradable soft systems and devices could then be manufactured in high number and deployed in the environment to fulfil their duties without the need to recover them, since they can safely degrade in the environment. The aim of the current Ph.D. project is the use of natural-derived and biodegradable polymers and substances as building blocks for the development of smart composite materials that could operate as functional elements in a soft robotic system or device. Soft mechanical properties and electronic/ionic conductive properties are here combined together within smart nanocomposite materials. The use of supersonic cluster beam deposition (SCBD) technique enabled the fabrication of cluster-assembled Au electrodes that can partially penetrate into the surface of soft materials, providing an efficient solution to the challenge of coupling conductive metallic layers and soft deformable polymeric substrates. In this work, cellulose derivatives and poly(3-hydroxybutyrate) bioplastic are used as building blocks for the development of both underwater and in-air soft electromechanical actuators that are characterized and tested. A cellulosic matrix is blended with natural-derived ionic liquids to design and manufacture completely biodegradable supercapacitors, extremely interesting energy storage devices. Lastly, ultrathin Au electrodes are here deposited on biodegradable cellulose acetate sheets, in order to develop transparent flexible electronics as well as bidirectional resistive-type strain sensors. The results obtained in this work can be regarded as a preliminary study towards the realization of full natural-derived and biodegradable soft robotic and electronic systems and devices

Structural Framework for Flight: NASA's Role in Development of Advanced Composite Materials for Aircraft and Space Structures

This serves as a source of collated information on Composite Research over the past four decades at NASA Langley Research Center, and is a key reference for readers wishing to grasp the underlying principles and challenges associated with developing and applying advanced composite materials to new aerospace vehicle concepts. Second, it identifies the major obstacles encountered in developing and applying composites on advanced flight vehicles, as well as lessons learned in overcoming these obstacles. Third, it points out current barriers and challenges to further application of composites on future vehicles. This is extremely valuable for steering research in the future, when new breakthroughs in materials or processing science may eliminate/minimize some of the barriers that have traditionally blocked the expanded application of composite to new structural or revolutionary vehicle concepts. Finally, a review of past work and identification of future challenges will hopefully inspire new research opportunities and development of revolutionary materials and structural concepts to revolutionize future flight vehicles

Data-driven Technology Foresight: Text Analysis of Emerging Technologies

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 산업·조선공학부, 2018. 2. 박용태.This dissertation argues for new directions in the field of technology foresight. Technology foresight was formulated on the basis of qualitative and participatory research. Initially, most foresight activities were triggered by the prospect of a handful number of experts, but recent studies highlight theoretical paradigm shifts toward a more comprehensive and data-driven approach to creating shared insights on the future of emerging technologies. Much of the research up to now, however, has been descriptive in nature, and a definite method of realizing the notion has not yet been addressed in the existing literature to a large extent. To this end, we have attempted to formalize the concept of data-driven technology foresight by incorporating unconventional data sources – future-oriented web data, Wikipedia data, and scientific publication data – and different analytical tools – Latent Semantic Analysis, IdeaGraph, and Morphological Analysis. Four distinct foresight frameworks were proposed for the proactive management process of emerging technologies: impact identification, impact analysis, plan development, and technology ideation. The study was guided by the following research questions: (1) what kinds of data sources are available on the web and which of those are considered useful in foresight studies? (2) Where could we incorporate these data sources and which techniques are most suitable for the given purposes? (3) Which foresight-related fields would particularly benefit from applying a data-driven approach and what are the positive effects? The proposals outlined should be considered exploratory and open-ended. It is designed to determine the nature of the problem, rather than to offer definitive and conclusive answers. Nevertheless, the proposed scheme may well provide not just a rationale but a theoretical grounding for this newly introduced notion. This dissertation is expected to yield a foothold for the readers to better comprehend and act on this new shift in the field of technology foresight.Chapter 1 Introduction 1 1.1 Emergence of Technology Foresight 1 1.2 Towards a Data-driven Technology Foresight 3 1.3 Problem Statement 6 1.4 Dissertation Overview 8 Chapter 2 Data Sources and Methodologies 15 2.1 Data Sources 15 2.1.1 Future-oriented Web Data 15 2.1.2 Wikipedia Data 17 2.1.3 Scientific Publication Data 19 2.2 Methodologies 21 2.2.1 Latent Semantic Analysis (LSA) 21 2.2.2 IdeaGraph 25 2.2.3 Morphological Analysis (MA) 29 Chapter 3 Foresight for Impact Identification 31 3.1 Introduction 32 3.2 Emerging Technology and its Social Impacts 36 3.2.1 Distinctive Nature of Emerging Technology 36 3.2.2 Technology Assessment 39 3.3 LSA for Constructing Scenarios 43 3.4 Research Framework 44 3.4.1 Step 1: Data Collection 46 3.4.2 Step 2: Scenario Development 49 3.4.2.1 Pre-LSA: Preprocessing Future-oriented Web Data 49 3.4.2.2 LSA: Applying Latent Semantic Analysis 52 3.4.2.3 Post-LSA: Constructing Scenarios 54 3.5 Illustrative Case Study: Drone Technology 55 3.6 Discussion 65 3.6.1 Categorization of Social Impacts 65 3.6.2 Comparative Analysis 72 3.6.3 Implication for Theory, Practice, and Policy 74 3.7 Conclusion 76 Chapter 4 Foresight for Impact Analysis 79 4.1 Introduction 80 4.2 Uncertainty and Complexity 82 4.3 Data-driven Foresight Process 84 4.4 Scenario Building Beyond the Obvious 86 4.4.1 Capturing Plausibility using LSA 90 4.4.2 Capturing Creativity using IdeaGraph 92 4.5 Research Framework 93 4.5.1 Step 1. Pre-Analysis: Data Preparation 94 4.5.1.1 Target Technology Selection 94 4.5.1.2 Data Acquisition 95 4.5.1.3 Data Preprocessing 95 4.5.2 Step 2. Text Analysis: Scenario Building 96 4.5.2.1 General Glimpse using Overt Structures 96 4.5.2.2 Hidden Details using Latent Structures 98 4.5.3 Step 3. Post-Analysis: Analytical Interpretation 101 4.5.3.1 Individual Impact Scenario 101 4.5.3.2 Overall Latent Impacts 101 4.6 Illustrative Case Study: 3D Printing Technology 102 4.7 Discussion 110 4.7.1 Scenarios Beyond the Obvious 110 4.7.2 Comparative Analysis 113 4.8 Conclusion 115 Chapter 5 Foresight for Plan Development 117 5.1 Introduction 118 5.2 Theoretical Paradigm Shift 120 5.2.1 Technology-focused vs. Society-focused 120 5.2.2 Co-evolution of Technology and Society 122 5.2.3 Responsible Development 125 5.3 Methodological Paradigm Shift 127 5.3.1 Participatory Approach 127 5.3.2 Data-driven Approach 129 5.4 Rationale for using LSA 131 5.5 Research Framework 132 5.5.1 Step 1. Envisioning Social Issues 133 5.5.1.1 Collection of Future-oriented Web Data 133 5.5.1.2 Construction of Impact Scenarios 135 5.5.1.3 Conceptualization of Impact Scenarios 137 5.5.2 Step 2. Deriving Technical Solutions 138 5.5.2.1 Collection of Scientific Publication Data 138 5.5.2.2 Construction of Solution Concepts 139 5.6 Illustrative Case Study: Autonomous Vehicle 140 5.7 Discussion 149 5.7.1 Comparative Analysis 149 5.7.2 Major Strengths in Envisioning Social Impacts 152 5.7.3 Major Strengths in Overviewing Solutions 154 5.8 Conclusion 156 Chapter 6 Foresight for Technology Ideation 158 6.1 Introduction 159 6.2 Related Studies 161 6.2.1 Generating Creative Ideas 161 6.2.2 Data-driven Morphological Analysis 163 6.3 Technology Foresight using Wikipedia 165 6.3.1 Wikipedia as a Good Remedy 165 6.3.2 Preliminaries: How to Apply Wikipedia 168 6.4 Research Framework 173 6.4.1 Basic Model 174 6.4.2 Extended Model 175 6.4.2.1 Phase 1: Preliminary Phase 177 6.4.2.2 Phase 2: Dimension Development Phase 177 6.4.2.3 Phase 3: Value Development Phase 179 6.4.2.4 Phase 4: Sub-dimension Development Phase 182 6.5 Illustrative Case Study: Drone Technology 183 6.5.1 Basic Model 183 6.5.2 Extended Model 185 6.6 Comparative Analysis 193 6.6.1 Experimental Setup 193 6.6.2 Comparison of Results 195 6.7 Intrinsic Limitations of Applying Wikipedia 199 6.8 Conclusion 201 Chapter 7 Concluding Remarks 203 Bibliography 211 Appendix 236 Appendix A Result of overt and latent structures of each impact scenario 236 Appendix B Result of Wikipedia-based morphological matrix (basic model) 240 Appendix C Result of Wikipedia-based morphological matrix using superordinate seed terms (extended model) 241 Appendix D Result of Wikipedia-based morphological matrix after applying subordinate value seed terms (extended model) 243 Appendix E Result of Wikipedia-based morphological matrix after developing sub-dimensions (extended model) 247Docto