Toward electronic design automation for electronic textiles: a knowledge-based design framework and case study of design rules for electronic textile circuits

Abstract

Textile circuit boards (TCBs) present a promising solution to the limitations of rigid printed circuit boards (PCBs) in wearable electronics applications. However, the development of TCBs remains fragmented, lacking standardization and structured design methodologies. This dissertation addresses this gap by developing a system-level framework to support the design and fabrication of textile circuits, with a focus on the stitching method as a representative manufacturing approach. The research was conducted in three distinct phases. Phase one focused on collecting and formalizing expert knowledge, drawing from multiple sources, including expert interviews with e-textile practitioners, a synthesis of existing literature, and experiential insights gained through research through design (RtD) case study conducted by the designer-researcher. Phase one uncovered key challenges, major variables, performance indicators used to evaluate system requirements, and common pain points in current design and manufacturing practices. The analysis of these data sources revealed core categories and design variables essential for enabling a more structured approach to textile circuit development. In phase two, these identified categories were translated into a hierarchical design framework tailored to electronic design automation (EDA) for e-textiles, that was validated through a second round of interviews with lead experts. Phase three involved characterizing selected circuit design and fabrication variables, such as trace (pathway) spacing, trace width, trace straightness, and trace resistance to translate the framework into design rules and to explore how these parameters influence manufacturers’ documentation, such as datasheets. The goal of phase three is to inform the development of data-driven electronic design automation systems that enhance repeatability, reliability, and communication between designers and manufacturers. Results from the three phases demonstrated that: (1) Key system variables, such as stitch type, substrate behavior, and circuit layout, interact in complex ways that are not currently documented or standardized, but are central to both design intent and system performance, (2) A hierarchical framework can successfully organize these variables into application objectives, standards, design rules, and methods, thus supporting structured decision-making and enabling integration with EDA tools, and (3) Experimental characterization revealed how fabrication parameters like thread type, fill density, and cleaning status significantly impact trace geometry and electrical resistance, providing a foundation for translating framework logic into actionable, data-driven design rules. Overall, this work identifies the core functions an EDA tool for e-textiles must perform to support reliable and efficient design. By analyzing the design processes, input variables, and performance considerations specific to textile circuits, we outline the functional requirements such an EDA tool should fulfill. This includes understanding the types of input variables designers rely on, the constraints they navigate, and the outputs or guidance the tool should generate. Once these foundational elements are defined, a series of targeted, illustrative examples are used to show how these functions might be realized within an EDA tool. This approach formalizes TCB design practices by linking empirical data and expert knowledge through a conceptual framework, ultimately advancing standardization and enabling more scalable, consistent production in textile circuits.