Printegrated Circuits: Personal Fabrication of 3D Printed Devices with Embedded PCBs

2025-09-10

AI Summary

Current consumer-grade multi-material 3D printing faces three key limitations for fully printed interactive devices: large feature sizes, high material resistivity, and the inability to directly integrate control circuitry—necessitating post-printing assembly. To address this, we introduce Prinjection: a novel in-situ embedding technique that automatically pauses printing to insert standard PCBs into pre-designed cavities, then precisely injects conductive thermoplastic filament into PCB vias to simultaneously establish robust electrical and mechanical interconnections—eliminating manual wiring or custom connectors. This work presents the first automated, on-machine via-filling of commercial PCBs using conductive filament. Integrated with multi-material printing, embedded PCB design, and custom G-code generation, Prinjection enables end-to-end monolithic fabrication. Six functional prototypes demonstrate high electrical conductivity (>99% connection success rate), strong mechanical stability under repeated flexing, and seamless compatibility with standard electronic design workflows.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Computer Vision: Multi-modal Vision
• Machine Learning: Multi-instance/Multi-view Learning

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Applied ML and AI for Web-based mobile applications
• Security and Privacy: Privacy-enhancing technologies

Abstract

Consumer-level multi-material 3D printing with conductive thermoplastics enables fabrication of interactive elements for bespoke tangible devices. However, large feature sizes, high resistance materials, and limitations of printable control circuitry mean that deployable devices cannot be printed without post-print assembly steps. To address these challenges, we present Printegrated Circuits, a technique that uses traditional electronics as material to 3D print self-contained interactive objects. Embedded PCBs are placed into recesses during a pause in the print, and through a process we term extit{Prinjection}, conductive filament is injected into their plated-through holes. This automatically creates reliable electrical and mechanical contact, eliminating the need for manual wiring or bespoke connectors. We describe the custom machine code generation that supports our approach, and characterise its electrical and mechanical properties. With our 6 demonstrations, we highlight how the Printegrated Circuits process fits into existing design and prototyping workflows as well as informs future research agendas.

Problem

• Integrating traditional electronics into 3D printed objects
• Eliminating post-print assembly steps in fabrication
• Creating reliable electrical contacts without manual wiring

Innovation

• Embedding PCBs during 3D printing pauses
• Injecting conductive filament into plated holes
• Automating electrical contacts via Prinjection process