Academic literature on the topic 'Contour Crafting technology'

Contour Crafting is a novel technology in construction industry based on 3D printing that uses robotics to construct free form building structures by repeatedly laying down layers of material such as concrete. It is actually an approach to scale up automatic fabrication from building small industrial parts to constructing buildings. However, there are little information about contour crafting (CC) in current use; present paper aims to describe the operational steps of creating a whole building by the machine reviewing relevant literature. Furthermore, it will represent the advantages of CC usage compared to traditional construction methods, as well as its applicability in construction industry.

Contour Crafting is a digitally controlled construction process invented by Professor Behrokh Khoshnevis that fabricates components directly from computer models, using layered fabrication technology. By obviating the need for formwork used in traditional concrete construction, CC can reduce costs and construction times significantly. The technique has great potential as a robotic form of construction reliant on relatively minimal human labor as a form of construction in relatively hazardous environments, such as the Moon with its radiation levels that can prove highly damaging. Current research funded by NASA has been exploring the potential for using CC on the Moon to build structures making use of readily available regolith that is found in great abundance on the surface of the Moon. This article offers an overview of this research and evaluates the merits of using CC on the Moon.

Background: 3D printing (3DP) is an emerging technique for fabrication of a variety of structures and complex geometries using 3D model data. In 1986, Charles Hull introduced stereolithography technique that took advances to beget new methods of 3D printing such as powder bed fusion, fused deposition modeling (FDM), inkjet printing, and contour crafting (CC). Being advantageous in terms of less waste, freedom of design and automation, 3DP has been evolved to minimize incurred cost for bulk production of customized products at the industrial outset. Due to these reasons, 3DP technology has acquired a significant position in pharmaceutical industries. Numerous polymers have been explored for manufacturing of 3DP based drug delivery systems for patient-customized medication with miniaturized dosage forms. Method: Published research articles on 3D printed based drug delivery have been thoroughly studied and the polymers used in those studies are summarized in this article. Results: We have discussed the polymers utilized to fabricate 3DP systems including their processing considerations, and challenges in fabrication of high throughput 3DP based drug delivery systems. Conclusion: Despite several advantages of 3DP in drug delivery, there are still a few issues that need to be addressed such as lower mechanical properties and anisotropic behavior, which are obstacles to scale up the technology. Polymers as a building material certainly plays crucial role in the final property of the dosage form. It is an effort to bring an assemblage of critical aspects for scientists engaged in 3DP technology to create flexible, complex and personalized dosage forms.

3D concrete printing is a perspective technology for sustainable construction and realization of sophisticated architectural projects. The current research proposes the thermal engineering calculation of wall structure based on the 3D printed concrete element of a total thickness of 150 mm with the internal air layer about 75 mm. The 3D printing mixture was designed with the addition of perlite as filler in the dosage of 8 % by weight of cement. The printing process was performed by the 3D printer of Contour Crafting type through the nozzle with a size of 20 mm. The thermal engineering calculation was implemented for the A++ energy consumption class. The wall structure based on the 3D printed concrete element with perlit has the thermal resistance comparable with one for wall structures based on brick and aerated concrete. The total thickness of the designed wall structure with 3D printed concrete element decreased by 100 mm and 50 mm in comparison with wall structures based on brick and aerated concrete, respectively. In addition to the thermal engineering calculations, the visual assessment of the surface quality of 3D printed concrete wall elements was performed.

IntroductionIn 2016, the online cause #Mission22 went viral on social media. Established to raise awareness about high suicide rates among US military veterans, the campaign involves users posting a video of themselves doing 22 push-ups for 22 days, and on some platforms, to donate and recruit others to do the same. Based on a ‘big data’ analysis of Twitter data (over 225,883 unique tweets) during the height of the campaign, this article uses #Mission22 as a site in which to analyse how people depict, self-represent and self-tell as moral subjects using social media campaigns. In addition to spotlighting how such movements are mobilised to portray moral selves in particular ways, the analysis focuses on how a specific online cause like #Mission22 becomes popularly supported from a plethora of possible causes and how this selection and support is shaped by online networks. We speculate that part of the reason why Mission22 went ‘viral’ in the highly competitive attention economies of social media environments was related to visual depictions of affective bodily, fitness and moral practices.Web 2.0 Culture: Self and Mass DepictionWeb 2.0 culture such as social networking sites (eg., Facebook; Instagram), the advent of video sharing technologies (eg., YouTube) and more recently, micro-blogging services like Twitter have created new and transformative spaces to create, depict and display identity. Web 2.0 is primarily defined by user-generated content and interaction, whereby users are positioned as both consumer and producers, or ‘produsers’ of Web content (Bruns and Schmidt). Challenging traditional “broadcast” media models, Web 2.0 gives users a platform to produce their own content and for “the many” to communicate “with the many” (Castells). The growth of mass self communication, supported by broadband and wireless technologies, gives unprecedented power to individuals and groups to depict and represent their identities and relationships to a potential global audience.The rise of user-generated communication technologies dovetails with broader analyses of the changing contours of self and identity in late-modern times. Individuals in the early decades of the 21st century must take charge for how they depict, portray and self-tell as distinctive, unique and individual subjects (Beck and Beck-Gernsheim; Giddens; Bauman). As contemporary lives become less bound to the strictures of tradition, community and religion, the self becomes a project to be worked out and developed. These theorists suggest that via processes of individualisation, detraditionalisation and globalisation, contemporary subjects have become disconnected from the traditional coordinates of community and are thus faced with the imperative of self-construction and reinvention (Elliott and Lemert).More recently, theoretical and empirical work has attempted to interpret and evaluate how networks of mass self-depiction powered by new digital and wireless technologies are reshaping identity practices. For some theorists, like Bauman (Consuming 2) and Turkle, Web 2.0 is a worrying trend. Bauman suggests in the “confessional society” – think reality TV, talk shows, social media – people are compelled to curate and reflect upon their lives in the public realm. These public acts of self-depiction are part of a move to treating the self as a brand to be consumed, “as products capable of drawing attention, and attracting demands and customers” (Bauman and Lyon 33). The consumer quality of new communications sees connections replace relationships as social bonds become short-term and brittle. Turkle makes a similar argument, suggesting that our preoccupation with online curation centres on controlling our identities and depicting “perfect” versions of ourselves. The result is diminished forms of intimacy and connection; we preach authenticity and realness but practice self-curation and self-stylisation.A more positive body of literature has examined how Web technologies work as tools for the formation of self. This literature is based on more close-up and detailed readings of particular platforms and practices rather than relying on sweeping claims about technology and social change. Following Foucault, Bakardjieva & Gaden argue that personal blogs and social networking site (SNS) profiles constitute a contemporary technology of the self, whereby users employ Web 2.0 technologies in everyday life as practices of self care and self-formation. In a similar way, Sauter argues that SNSs, and in particular Facebook, are tools for self-formation through the way in which status updates provide a contemporary form of self-writing. Eschewing the notion of social media activity as narcissistic or self-obsessive, Sauter argues that SNSs are a techno-social practice of self-writing that facilitate individuals to “form relations to self and others by exposing themselves to others and obtaining their feedback” (Sauter 836). Other research has explored young people’s sustained use of social media, particularly Facebook, and how these sites are used to tell and archive “growing up” narratives and key rites of passage (Robards and Lincoln).One area of research that has been overlooked is how people use social media to construct and depict moral identity. Following Sauter’s arguments about the self work that occurs through networked self-writing, we can extend this to include the ethical self work performed and produced through online depictions. One exception is work by Hookway which analyses how people use blogs – an earlier Web 2.0 form – to write and self-examine their moral experiences. This research shows how bloggers use blogging as a form of online self-writing to construct a do-it-yourself form of morality that emphasises the self, emotions, body and ideals of authenticity. Hookway highlights the idea that morality is less about obedience to a code of rules or following external laws to becoming a particular moral person through a set of self-practices. Paralleling broader shifts in identity construction, people are no longer bound to the inherited guidelines of the past, morality becomes a project to be worked out, designed and depicted in relation to Others (Hookway).In Foucault’s terms, morality involves a process of ethical self-stylisation – an “aesthetics of existence” – based on “the ethical work of the self on the self” (Foucault 91). “Care of the self” involves a “set of occupations” or “labours” that connect and link the self to the Other through guidance, counselling and communication (Foucault 50). For Foucault, self-creation and self-care imply “care for others” as individuals perform a mutual concern with achieving an “art of existence”. This is a reciprocated ethics that obligates the individual to care for others in order to help them care for themselves.This stylisation of the ethical self has been drastically reshaped by the new opportunities for self-expression, belonging and communication offered in our digitally networked society. Digital worlds and spaces create new multi-media modes for individuals and groups to depict, perform and communicate particular moral identities and positions. Web 2.0 technologies are seeing the boundaries between the private and public sphere collapse as more people are willing to share the most intimate part of their moral lives with a diverse mix of strangers, friends, family and associates.The confessional quality of online spaces provide a unique opportunity to analyse “lay morality” or everyday moral understandings, constructions and depictions and how this is co-produced in relation to new technological affordances. Following Sayer (951), morality is defined as “how people should treat others and be treated by them, which of course is crucial for their subjective and objective well-being”. Morality is understood as a relational and evaluative practice that involves being responsive to how people are faring and whether they are suffering or flourishing.In this article, we use the #Mission22 campaign – a campaign that went “viral” across multiple social media platforms – as a unique site to analyse and visualise lay moral depictions and constructions. Specifically, we analyse the #Mission22 campaign on Twitter using a big data analysis. Much of the empirical work on online self construction and depiction is either purely theoretical in the vein of Bauman, Turkle and Sauter or based on small qualitative samples such as the work by Lincoln and Robards and Author A. This article is unique not only in investigating the crafting of moral depictions in Web 2.0 forums but also in the scale of the textual and visual representation of mass moral self-depictions it captures and analyses. Big Data Analysis of #Mission22 on TwitterIn order to empirically examine the #Mission22 campaign on Twitter, we used the Twitter API to collect over three months of tweets that contained the campaign hashtag (from 20 Aug. 2016 to 1 Dec. 2016). This resulted in a dataset of 2,908,559 tweets, of which 225,883 were non-duplicated (i.e., some tweets were collected multiple times by the crawler).There were 3,230 user accounts participating during this period, with each user tweeting 70 times on average. As Figure 1 shows, a sizeable percentage of users were quite active at the height of the campaign, although there is clearly a number of users who only tweeted once or twice. More specifically, there were 1,232 users (or 38%) who tweeted at least 100 times, and on the other hand 1080 users (or 33%) who only tweeted two times or less. In addition, a tiny number of ‘power users’ (18 or 0.006%) tweeted more than 400 times during this period. Figure 1: Frequency distribution of #Mission22 tweets for each user in the datasetTo get a sense of what users were talking about during the campaign, we constructed a wordcloud out of the text data extracted from the tweets (see Figure 2). To provide more information and context, usernames (preceded with @) and hashtags (preceded with #) were included along with the words, providing a set of terms. As a result, the wordcloud also shows the user accounts and hashtags that were mentioned most often (note that #Mission22 was excluded from the data as it, by definition of the data collection process, has to occur in every tweet). In order to remove meaningless terms from the dataset we applied several text processing steps. First, all terms were converted to lowercase, such that “Veteran” and “veteran” are treated as the same term. Next, we applied a technique known as term frequency-inverse document frequency (tf-idf) to the tweet text data. Tf-idf effectively removes terms that occur so frequently that they provide no interesting information (e.g., the term “mission22”), and also terms that occur extremely infrequently. Finally, we removed English “stop words” from the text data, thereby eliminating common words such as “the” and “and”. Figure 2: Wordcloud of the #Mission22 tweet contentAs Figure 2 shows, the most frequent terms revolve around the campaign message and call-to-action for suicide awareness, including, for example, “day”, “veteran”, “support”, “push-ups”, “band”, “challenge”, “suicide”, “fight”, and “alone”. A number of user accounts are also frequently mentioned, which largely relate to the heavily retweeted users (discussed further below). Furthermore, alongside the central #mission22 hashtag, a number of other popular hashtags were in circulation during the campaign, including “#veteran”, “#americasmission”, “#22kill”, and “#22adayis22toomany”. Table 1 provides the top 50 most frequently occurring terms in decreasing order.Table 1: Top 50 words in the #Mission22 tweet content (decreasing order)1-1011-2021-3031-4041-50day@mrbernardedlong@uc_vetsnothingveteran#veteranbetter@kappasigmauceverysupporteverydaybelieve@ucthetachimissionpush-upschallengetodaytakehelp@sandratxassuicidehaulone#22kill@defensebaronveteransawarenessjustsay@the_usofightaccepted@piedmontlax#veterans@nbcnewsaloneptsdgoodweaknessbandvets22kwrong#nevertrumpcimmunity [sic]#americasmissionshoutoutgodwillA surprising finding of our study is that the vast majority of tweets are simply just retweets of other users. The number of retweets was 223,666, which accounts for about 99% of all tweets in the dataset. Even more surprising was that the vast majority of these retweets are from a single tweet. Indeed, 221,088 (or 98%) of all tweets in the dataset were retweets of the following tweet that was authored on 2 March 2015 by @SandraTXAS (see Figure 3). Clearly we can say that this tweet went ‘viral’ (Jenders et al) in the sense that it became frequently retweeted and gained an increasing amount of attention due to its cumulative popularity and visibility over time. Figure 3: #1 most retweeted #Mission22 tweet – @SandraTXAS (https://twitter.com/SandraTXAS)This highly retweeted or viral #Mission22 tweet provides a point of departure to examine what aspects of the tweet content influence the virality or popularity of #Mission22 tweets during the height of the campaign. To do this, we extracted the next nine most retweeted tweets from our dataset, providing an analysis of the “top 10” retweets (including the @SandraTXAS tweet above). Figure 4: #2 most retweeted - @mrbernarded (https://twitter.com/mrbernarded/status/776221040582295553)This tweet was retweeted 715 times in our dataset. Figure 5: #4 most retweeted - @Mission22 (https://twitter.com/Mission22/status/799872548863414272)This was retweeted 317 times in our dataset. Figure 6: #4 most retweeted - @UCThetaChi (https://twitter.com/UCThetaChi/status/784775641430384640)This was retweeted 180 times in our dataset. Figure 7: #5 most retweeted - @PamKeith2016 (https://twitter.com/PamKeith2016/status/782975576550305792)This was retweeted 121 times in our dataset. Figure 8: #6 most retweeted - @PiedmontLax (https://twitter.com/PiedmontLax/status/770749891698122752)This was retweeted 105 times in our dataset. Figure 9: #7 most retweeted - @PiedmontLax (https://twitter.com/PiedmontLax/status/771181070066692098) This was retweeted 78 times in our dataset. Figure 10: #8 most retweeted - @PatriotBrother (https://twitter.com/PatriotBrother/status/804387050728394752) This was retweeted 59 times in our dataset. Figure 11: #9 most retweeted - @alexgotayjr (https://twitter.com/alexgotayjr/status/787112936644849664) This was retweeted 49 times in our dataset. Figure 12: #10 most retweeted - @csjacobson89 (https://twitter.com/csjacobson89/status/772921614044233729) This was retweeted 45 times in our dataset.DiscussionThis article has provided the first “big data” analysis of the #Mission22 movement that went viral across multiple social media platforms in 2016. We began by arguing that Web 2.0 has ushered in profound changes to how people depict and construct identities that articulate with wider transformations in self and identity in conditions of late-modernity. The “confessional” quality of Web 2.0 means individuals and groups are presented with unprecedented opportunities to “mass self-depict” through new communication and Internet technologies. We suggest that the focus on how Web technologies are implicated in the formation of moral subjectivities is something that has been overlooked in the extant research on identity and Web 2.0 technologies.Filling this gap, we used the #Mission22 movement on Twitter as an empirical site to analyse how contemporary subjects construct and visually depict moral identities in online contexts. A central finding of our analysis of 225883 Twitter posts is that most engagement with #Mission22 was through retweeting. Our data show that retweets were by far the most popular way to interact and engage with the movement. In other words, most people were not producing original or new content in how they participated in the movement but were re-sharing – re-depicting – what others had shared. This finding highlights the importance of paying attention to the architectural affordances of social media platforms, in this case, the affordances of the ‘retweet’ button, and how they shape online identity practices and moral expression. We use moral expression here as a broad term to capture the different ways individuals and groups make moral evaluations based on a responsiveness to how people are faring and whether they are suffering or flourishing (Sayer). This approach provides an emic account of everyday morality and precludes, for example, wider philosophical debates about whether patriotism or nationalistic solidarity can be understood as moral values.The prominence of the retweet in driving the shape and nature of #Mission22 raises questions about the depth of moral engagement being communicated. Is the dominance of the retweet suggestive of a type of “moral slacktivism”? Like its online political equivalent, does the retweet highlight a shallow and cursory involvement with a cause or movement? Did online engagement translate to concrete moral actions such as making a donation to the cause or engaging in some other form of civic activity to draw attention to the movement? These questions are beyond the scope of this article but it is interesting to consider the link between the affordances of the platform, capacity for moral expression and how this translates to face-to-face moral action. Putting aside questions of depth, people are compelled not to ignore these posts, they move from “seeing” to “posting”, to taking action within the affordances of the architectural platform.What then is moving Twitter users to morally engage with this content? How did this movement go viral? What helped bust this movement out of the “long tail distribution” which characterises most movements – that is, few movements “take-off” and become durable within the congested attention economies of social media environments. The Top 10 most retweeted tweets provide powerful answers here. All of them feature highly emotive and affective visual depictions, either high impact photos and statements, or videos of people/groups doing pushups in solidarity together. The images and videos align affective, bodily and fitness practices with nationalistic and patriotic themes to produce a powerful and moving moral cocktail. The Top 50 words also capture the emotionally evocative use of moral language: words like: alone, fight, challenge, better, believe, good, wrong, god, help, mission, weakness and will.The emotional and embodied visual depictions that characterise the the Top 10 retweets and Top 50 words highlight how moral identity is not just a cerebral practice, but one that is fundamentally emotional and bodily. We do morality not just with our minds and heads but also with our bodies and our hearts. Part of the power of this movement, then, is the way it mobilises interest and involvement with the movement through a physical and embodied practice – doing push-ups. Visually depicting oneself doing push-ups online is a powerful display of morality identity. The “lay morality” being communicated is that not only are you somebody who cares about the flourishing and suffering of Others, you are also a fit, active and engaged citizen. And of course, the subject who actively takes responsibility for their health and well-being is highly valued in neoliberal risk contexts (Lupton).There is also a strong gendered dimensions to the visual depictions used in #Mission22. All of the Top 10 retweets feature images of men, mostly doing push-ups in groups. In the case of the second most popular retweet, it is two men in suits doing push-ups while three sexualised female singers “look-on” admiringly. Further analysis needs to be done to detail the gendered composition of movement participation, but it is interesting to speculate whether men were more likely to participate. The combination of demonstrating care for Other via a strong assertion of physical strength makes this a potentially more masculinised form of moral self-expression.Overall, Mission22 highlights how online self-work and cultivation can have a strong moral dimension. In Foucault’s language, the self-work involved in posting a video or image of yourself doing push-ups can be read as “an intensification of social relations”. It involves an ethics that is about self-creation through visual and textual depictions. Following the more pessimistic line of Bauman or Turkle, posting images of oneself doing push-ups might be seen as evidence of narcissism or a consumerist self-absorption. Rather than narcissism, we want to suggest that Mission22 highlights how a self-based moral practice – based on bodily, emotional and visual depictions – can extend to Others in an act of mutual care and exchange. Again Foucault helps clarify our argument: “the intensification of the concern for the self goes hand in hand with a valorisation of the Other”. What our work does, is show how this operates empirically on a large-scale in the new confessional contexts of Web 2.0 and its cultures of mass self-depiction. ReferencesBakardjieva, Maria, and Georgia Gaden. “Web 2.0 Technologies of the Self.” Philosophy & Technology 25.3 (2012): 399–413.Bauman, Zygmunt. Liquid Modernity. Cambridge: Polity, 2000.———. Consuming Life. Cambridge: Polity, 2007.———, and David Lyon. Liquid Surveillance. Cambridge: Polity, 2013.Beck, Ulrich, and Elizabeth Beck-Gernsheim. Individualisation. London: Sage, 2001.Bruns, Axel, and Jan-Hinrik Schmidt. “Produsage: A Closer Look at Continuing Developments.” New Review of Hypermedia and Multimedia 17.1 (2011): 3–7.Dutta-Bergman, Mohan J. “Primary Sources of Health Information: Comparisons in the Domain of Health Attitudes, Health Cognitions, and Health Behaviors.” Health Communication 16.3 (2004): 273–288.Elliott, Anthony, and Charles Lemert. The New Individualism: The Emotional Costs of Globalization. New York: Routledge, 2006.Foucault, Michel. The Care of the Self: The History of Sexuality. Vol. 3. New York: Random House, 1986.Giddens, Anthony. Modernity and Self-Identity: Self and Society in the Late Modern Age. Cambridge: Polity, 1991.Hookway, Nicholas. “The Moral Self: Class, Narcissism and the Problem of Do-It-Yourself Moralities.” The Sociological Review, 15 Mar. 2017. <http://journals.sagepub.com/doi/abs/10.1177/0038026117699540?journalCode=sora>.Jenders, Maximilian, et al. “Analyzing and Predicting Viral Tweets.” Proceedings of the 22nd International Conference on World Wide Web (WWW). Rio de Janeiro, 13-17 May 2013.Kata, Anna. “Anti-Vaccine Activists, Web 2.0, and the Postmodern Paradigm: An Overview of Tactics and Tropes Used Online by the Anti-Vaccination Movement.” Vaccine 30.25 (2012): 3778–89.Lincoln, Sian, and Brady Robards. “Editing the Project of the Self: Sustained Facebook Use and Growing Up Online.” Journal of Youth Studies 20.4 (2017): 518–531.Lupton, Deborah. The Imperative of Health: Public Health and the Regulated Body. London: Sage, 1995.Sauter, Theresa. ‘“What's on Your Mind?’ Writing on Facebook as a Tool for Self-Formation.” New Media & Society 16.5 (2014): 823–839.Sayer, Andrew. Why Things Matter to People: Social Science, Values and Ethical Life. Cambridge: Cambridge University Press, 2011.Smith, Gavin J.D., and Pat O’Malley. “Driving Politics: Data-Driven Governance and Resistance.” The British Journal of Criminology 56.1 (2016): 1–24.Turkle, Sherry. Reclaiming Conversation: The Power of Talk in a Digital Age. Penguin: New York, 2015.

This paper introduces a new concept for a contour crafting construction system. Contour crafting is a relatively new layered fabrication technology that enables automated construction of whole structures. The system proposed here consists of a mobile contour crafting platform driven by a translational cable-suspended robot. The platform includes an extrusion system for laying beads of concrete as well as computer-controlled trowels for forming the beads as they are laid. This system is fully automated and can be used to construct concrete structures rapidly and economically. The novel attributes of this system enable significant improvements over other proposed contour crafting systems, including easier portability, lower cost, and the potential to build much larger structures. This paper presents the kinematics and statics of the proposed system, and uses the reachable workspace of the robot as well as the corresponding cable tensions to approximate the maximum size structure that can be built using this manipulator.

Contour crafting (CC) is a new technology that is proposed for construction. Formerly we presented a cable-suspended robot to implement CC technology with Cartesian motion. The current paper proposes an improved Contour-Crafting-Cartesian-Cable (C4) robot. Although the new concept is preferable in structural design, here we compare the original and improved C4 robot concepts with regard to kinematics, workspace, and stiffness.

This research explores mega-scale additive manufacturing, using fresh concrete. In traditional concreting, rigid forms mold and protect young concrete, like an exoskeleton. Typically, these forms are not removed until the maturing material has developed considerable load-bearing strength. Conversely, Contour Crafting, an automated construction technology under development at the University of Southern California, proposes to rapidly fabricate civil structures additively — layering continuous ribbons of fresh unconfined concrete. The process, which is akin to 3-D printing, leverages a special polymer-modified concrete which is both highly workable and shape–stable. However, without exoskeleton, the freshly layered concrete must be load-bearing immediately upon placement. This is an unprecedented structural requirement, and little has been done to substantiate uncured concrete as a load-bearing member. This research establishes the build rates and material health monitoring necessary to erect these structures safely, and demonstrates the Contour Crafting process is viable.