The Automated Design and Manufacturing Laboratory (ADML) is an automated assembly line located in the Engineering Product and Innovation Center (EPIC) that serves as the lab component for the course ME345: Automation and Manufacturing Methods. Over the semester the students learn how to program each automated component of the system, including Computer Numerically Controlled (CNC) mills, Universal Robot's 6 axis robotic arm, cameras, and Programmable Logic Controllers (PLC). Students then learn how to integrate each component together to develop a completely automated manufacturing process using an in-house manufacturing execution software. This integrated system is then used by the students to automatically manufacture new products of their own design that provide a societal benefit. Since 2019 multiple undergraduate students have worked on augmenting the ADML's capability with printing electronics by implementing Direct Ink Writing (DIW) based 3D printing and vacuum based pick and place into the ADML's assembly robot. Using these new capabilities, students in the ME345 will be able to design and manufacture electronic circuits. Moreover, a graduate level course will be developed based on this new addition to the ADML. The aim of this Thesis is to continue the work of previous students by finalizing the hardware and software necessary for the pick and place of electronic components and developing a conductive ink for electrical wiring and interconnects. A three component ink comprised of silver flake and a copolymer solution of acrylates/polytrimethylsiloxymethacrylate in a isododecane solvent was developed. This ink is biocompatible so it can be used by students without any hazard concern. It also exhibits a high degree of adhesion to the high-density polyethylene (HDPE) stock parts currently used in the ADML to ensure strong bonding to the electrical components. The mixing process, ink ingredient concentrations, and print parameters (i.e., extrusion pressure, print speed, and nozzle standoff distance) were optimized for compatibility with DIW based 3D printing, consistent and clog-free extrusion throughout the printing process, print fidelity, and a high electrical conductivity within approximately 1-2 orders of magnitude of bulk silver. / 2025-05-24T00:00:00Z

Non-planar additive manufacturing (AM) technologies, such as microextrusion 3D printing processes, offer the ability to fabricate conformal electronics with impressive structure and function on curvilinear substrates. Although various available methods offer conformal 3D printing capability on objects with limited geometric complexity, a number of challenges remain to improve feature resolution, throughput, materials compatibility, resultant function and properties of printed components, and application to substrates of varying topography. Hence, the overall objective of this dissertation was to create new non-planar AM processes that are compatible with personalized and anatomical computer-aided design workflows for the fabrication of conformal electronics and form-fitting wearables. After reviewing the current state of knowledge and state of the art, significant challenges in non-planar AM have been identified as: 1) limited non-planar AM path planning capability that synergizes with personalized or anatomical object surface modification, 2) limited approaches for printed and non-printed component integration on non-planar substrates. To address these challenges, a template-based reverse engineering workflow is proposed for conformal 3D printing electronics and form-fitting wearable devices on anatomical structures. This work was organized into three complementary tasks that enhance non-planar AM capabilities: 1） To achieve anatomical tissue-sensor integration, 3D scanning-based point cloud data acquisition and customized 3D printable conductive ink are proposed for capturing the topographical information of patient-specific malformations and integrating conformal sensing electronics across anatomical tissue-device interface. 2） To fabricate conformal antennas on flexible thin-film polymer substrates, a versatile method for microextrusion 3D printing of conformal antennas on thin film-based structures of random topography is proposed to control the ink deposition process across the curvilinear surfaces of freeform Kapton-based origami. 3） To simplify the fabrication process of form-fitting wearable devices with fiber-based form factors and self-powered capability, an innovative 3D printing process is proposed to achieve coaxial multi-material extrusion of metal-elastomer triboelectric fibers. By developing new advanced non-planar printing processes and conformal toolpath programming strategies, the utility of non-planar AM could be further expanded for fabricating various personalized implantable and wearable multi-functional systems, including novel 3D electronics. In summary, this work advances capability in additive manufacturing processes by providing new advances in multi-material extrusion processes and personalized device design and manufacturing workflows. / Doctor of Philosophy / The ability to assemble electronic devices on three-dimensional objects with complex geometry is essential for developing next-generation wearable devices. Additive manufacturing processes, commonly referred to as 3D printing, now offer the ability to fabricate conformal electronics on surfaces and objects with non-planar geometry. This dissertation aims to expand non-planar 3D printing capabilities for applications to objects with anatomical or personalized structures, such as patient-specific malformation and origami. The proposed methods in this dissertation are focused on addressing challenges, such as the acquisition of object 3D topographical data, material selection, and tool path programming for objects that exhibit anatomical geometry. The utility of the proposed methods is demonstrated with practical applications to 3D-printed conformal electronics and wearable devices for monitoring human behavior and organ healthcare. This dissertation contributes to improving manufacturing capability and outcomes of 3D-printed form-fitting wearable and implantable devices. Future work may emphasize developing biocompatible functional ink and toolpath programming algorithms with real-time adaptation capability.