This thesis proposes the use of seashells and their behaviours to create a methodological framework for designing wearable knitted sculptures for the body. The behaviours of exposure, protection, growth, and constriction are used to map out the cyclic life pattern of the woman's body and explore its growth. This cyclic view of the woman's body is rooted in re-imagined storytelling of classic myths, continuing the traditional practice of retelling stories to fit or change the perception of current social constructions. The mythology of maiden-mother-crone is aligned with seashell growth cycle, creating a conceptual dialogue between the two. This creates a dynamic storytelling within the research which informs the behaviour and look of the individual pieces. The work used a methodology that explored how digital tools can be incorporated into the sketching process. Experiments, digital and physical, were conducted to support and deepen the exploration of the concept regarding seashells growing on human bodies in both the metaphorical and physical sense. The methodology included the notion of Tableau vivant, a tableau-like performance by the model that is captured as a still image to convey the design expression. The collection tells a story where each piece is a point in the lifespan of shells and humans, drawing parallels between the individual growth cycles and establishing meeting points through body characteristics and social symbolism. This makes the textiles not only an extension of the body with transcribed feelings and personalities but also a representation of it. This thesis presents a twofold result, the five-pieced collection of wearable garments and a series of photographed images that contextualize the collections’ interaction with the woman's body.

Pearly layers in seashells, also known as nacreous layers, are reported to be three orders of magnitude tougher than their primary constituent, aragonite. Their high toughness is attributed to a particular structure of alternating layers of natural ceramic and polymer materials. This work tries to emulate it using engineering materials. The thickness, strength, and stiffness of the ceramic layer; the thickness, stiffness, strength, and toughness of the polymer interface layer; and the number of layers are the factors that contribute to different degrees. Furthermore, understanding the relative contribution of different toughening mechanisms in nacre would enable identification of key parameters to design tough engineered ceramics. As a step towards that, in this thesis, layered ceramic beams replicating nacre were studied analytically, computationally, and experimentally. The insights and findings from these studies were then used to develop a new method to make tough layered ceramics mimicking nacre. Subsequently, the use of layered ceramics for armour applications was evaluated. Based on analytical numerical and experimental studies, we observed that the strength of the layers is a key factor to replicate the high toughness of nacre in engineered ceramics. We also demonstrated that, crack deflection and bridging observed in nacre in studies elsewhere, occur due to the high strength of platelets. Based on these findings, the new method developed in this study uses green alumina-based ceramic tapes stacked with screen printed stripes of graphite. During sintering, graphite oxidizes leaving empty channels in the stack. These channels were filled with tough interface materials afterwards. As a result, a ceramic- polymer composite with more than 2-fold increase in toughness was developed. Subsequently, we evaluated layered ceramics for armour applications based on numerical analysis validated with experiments. Consistent to the trends in literature, we observed that layers degrade the resistance to ballistic impact. However, improved energy absorption is demonstrated in layered ceramics. These conflicting dual trends were not presented and quantified in any earlier studies conducted elsewhere. Another new observation not documented earlier is the effect of interface strength. Using an interface material of sufficient strength, penetration resistance of layered ceramics can be improved beyond monolithic ceramics. Using these findings, new layered ceramic armour can be designed that is cost- effective and better performing than monolithic ceramics.

Rugosidad superficial, acrílico dental, pulido dental, conchas de moluscos. Surface roughness, dental acrylic, dental polish, seashells. / Objetivo: Evaluar in vitro la rugosidad superficial de una pasta experimental de pulido para acrílico a base de conchas de moluscos. Materiales y métodos: Un total de 74 especímenes de acrílico fueron divididos en 2 grupos (n=37). Todos los especímenes fueron confeccionados con una matriz metálica (14x5x6 mm) y pulidos con una pasta experimental a base de Donax Obesulus y piedra pómez con un tamaño de partículas de 15µm, respectivamente para cada grupo. La rugosidad superficial inicial y final fue evaluada con un rugosímetro luego del pulido de los especímenes. Los datos fueron analizados mediante estadística descriptiva (media, mediana, desviación estándar y rango intercuartílico) e inferencial (Prueba de Wilcoxon pareada y Prueba de U de Mann Whitney) (p<0.05). Resultados: Los especímenes pulidos con piedra pómez mostraron mayores valores de rugosidad (0,45±0,12 µm); mientras que los especímenes que fueron pulidos con la pasta experimental tuvieron menores valores de rugosidad (0,50±0,07µm). Pese a ello, no se encontró diferencia estadísticamente significativa entre la rugosidad superficial de la pasta experimental y el grupo control (p = 0.309). Conclusiones: La pasta experimental a base de conchas de moluscos redujo los valores de rugosidad superficial en las superficies del acrílico dental. / Objective: To evaluate in vitro the surface roughness of an experimental polishing paste for acrylic based on seashells. Materials and methods: A total of 74 acrylic specimens were divided into 2 groups (n = 37). All specimens were made with a metal matrix (14x5x6 mm) and then polished with an experimental paste and pumice stone with a particle size of 15 µm, respectively for each group. Initial and final surface roughness was evaluated after polishing the specimens. The data were analyzed using descriptive (mean, median, standard deviation and interquartile range) and inferential statistics (Wilcoxon signed-rank test and Mann Whitney U test) (p<0.05). Results: Specimens polished with pumice had higher roughness values (0.16 ± 0.06 µm), whereas specimens polished with the seashell powder had lower values in their surface roughness (0.09 ± 0.03 µm). Despite this, no statistically significant difference was found between the surface roughness of the experimental paste and the control group (p = 0.309). Conclusions: The experimental paste made of seashells reduced the surface roughness values on dental acrylic surface. / Tesis