Designing Structurally Adaptable Multi-mode Products Using Emerging Constrained Layer Pneumatic System Technologies

Abstract

In our designed environment, we interact with a wide variety of products, ranging from simple to complex, each offering different sets of functionalities to meet dynamically changing user needs. Most conventionally designed products offer a stationary set of functions, unable to dynamically address users' changing context-specific diverse array of needs. Multi-mode non-reconfigurable and modularly reconfigurable products enable multiple sets of functionalities (i.e., modes) but inevitably become bulkier, heavier, and more complex to use with increasing functionality and modality. However, a novel genre of products - structurally adaptable multi-mode products - presents significant potential to cater more efficiently to changing needs by offering multiple sets of functionalities by transforming their structural configurations on demand through multiple operation states in different modes. To enable these transformations, this dissertation identifies and develops a novel pneumatically activated architecture, constrained layer pneumatic systems, as a promising technological platform. These systems provide customizable, lightweight, space-saving, and cost-effective solutions to design multi-mode products. Constrained layer pneumatic systems produce numerous functionalities, such as complex three-dimensional actuation motions, structural property changes, and sensing capabilities, through their hierarchically arranged architectural components (e.g., cells) that are constrained internally and/or externally. Pneumatic affordances and fundamental behaviors are classified, linking subcellular features to system architecture, functionality, and operation. This approach aids in describing and understanding these systems and offers building blocks for designing structurally adaptable multi-mode products tailored to specific user-product interaction contexts. A comprehensive hierarchical functional architectural decomposition approach is presented to enable a detailed understanding of product system hierarchy. This approach allows designers to systematically capture the relationships among architectural, functional, operational, and performance system aspects through the architectural and functional hierarchies comprising cell, ensemble, unit, assembly, and system levels. This facilitates various analysis, synthesis, and re-synthesis design methods, enabling incremental improvements, replacements, and speculative designs of structurally adaptable multi-mode products based on existing ones. Ten distinct goal-oriented design strategies are formulated and grouped under redesign, incremental innovation, and radical innovation categories, providing a systematic approach to re-synthesize structurally adaptable multi-mode product concepts. To demonstrate an effective way of systematically exploring a hierarchically organized broad architectural design space, a specific type of a constrained layer pneumatic system, internally tiled pneumatic textiles, is selected as an architectural case study. Three consecutive studies comprising a tile architectural study, a design coupling study, and an architectural feature variations study, provide an understanding of the hierarchical architectural structure, functionality and operation, and the interdependent relationship between architectural and parametric design, as well as the performance of the competing functionalities. This provides a basis to conduct a parametric design case study focusing on the design of a specific structurally adaptable multi-mode product, the moldable active cargo blanket, with tailored multi-modal performance attributes. A predictive empirical model is developed and validated based on a half-factorial design-of-experiments, capturing the trading-off performances of the functionalities provided by moldable active cargo blanket, enabling an algebraic tailoring method for selecting tile geometry design variables to achieve intended design outcomes. The method is demonstrated by tailoring the performance of three different cargo blankets for various contexts, with their performances experimentally validated against design goals. This design science foundation fosters a diverse range of rich user-product interaction opportunities by addressing users' varied needs through a new generation of multi-mode products offering functional adaptability via their adaptive structures.