Adaptive 3D Printing of Resonant-Enhanced Microsensors

The ability to integrate wireless microelectronics on the surfaces of existing biomedical devices can functionalize an otherwise passive construct with advanced sensing capability. The digital freeform fabrication approach directly integrates sensors on a clinically proven device without requiring significant structural modification, lowering the clinical barrier for electronic integration. However, achieving microelectronics integration on biomedical devices (e.g., joint replacement implants) with microextrusion-based 3D printing remains challenging. Biomedical devices are typically geometrically complex three-dimensional constructs requiring extensive surface topological scanning, electronic design and calibration. Here, we develop a microscale closed-loop printing system aided with a laser displacement sensor capable of printing 3D resonant-enhanced microsensors with trace widths as small as 30 μm on a broad range of 3D constructs. The system adapts to the 3D surfaces, achieving conformal printing without requiring extensive alignment of the target substrate with the generated print path. As a proof of concept, we will demonstrate the ability to integrate sensors on biomedical devices such as joint-replacement implants and biological constructs such as bone. Finally, the sensors can be robustly and wirelessly interrogated with high sensitivity using readout techniques that leverage the enhanced sensitivity of systems at special degeneracies, enabling a fundamentally new approach to integrating electronics on existing biomedical devices.