SenScaffold: A 3D-Printed Porous Dielectric Resonator as a Self-Sensing Scaffold

P. Sofokleous, E. Paz, F.J. Herraiz-Martínez

IEEE Sensors Journal Vol. 26, nº. 10, pp. 15256 - 15270

Summary:

This study presents a proof of concept for the design, fabrication, and characterization of a 3D-printed porous dielectric resonator (DR) scaffold for real-time, non-invasive monitoring of bone regeneration. A scaffold is a biocompatible, porous structure that supports cell attachment, growth, and tissue formation to heal large bone defects. Full-wave simulations confirm that the porous DR exhibits electromagnetic (EM) field distributions similar to a conventional rectangular DR, with a frequency shift due to its porosity. The self-sensing scaffold is fabricated via Fused Deposition Modeling (FDM) 3D printing using polylactic acid (PLA) reinforced with zirconia (PLA_ ZrO₂). It is then covered with one or more printed layers of PLA reinforced with hydroxyapatite (PLA_HA) to simulate varying stages of bone growth, as PLA_HA possesses a relative permittivity similar to that of natural bone. Theoretical and experimental results demonstrate that the resonant frequency shifts inversely with HA layer thickness, validating the scaffold's ability to function as a passive sensor for detecting and tracking tissue regeneration. A comparison of simulated and experimental field distributions confirms that the porous DR sustains a resonant mode suitable for interrogation via a coaxial probe coupled to the scaffold in the near-field region. Experimental evaluation reveals a high sensitivity of 500 MHz/mm during the initial stages of bone growth (up to 1 mm) and 380 MHz/mm for subsequent stages, confirming the system’s capability for early-stage clinical monitoring. This work represents an initial step toward a clinically relevant monitoring system, demonstrating that porous DR scaffolds can act as functional biosensors with integrated self-sensing capabilities. The ability to monitor bone regeneration via EM interrogation offers a scalable, wireless, non-invasive approach for real-time biomedical diagnostics. A key advantage of self-sensing scaffold is that it functions itself as a sensor, eliminating the need for additional components or devices within the body. The same structure that supports bone regeneration also enables real-time monitoring.

Spanish layman's summary:

Se desarrolla un andamio impreso en 3D (“scaffold”) que no solo favorece la regeneración ósea, sino que también permite monitorizarla en tiempo real sin procedimientos invasivos. El sistema detecta el crecimiento del hueso mediante cambios en la respuesta electromagnética del andamio.

English layman's summary:

A 3D-printed scaffold is developed to both support bone healing and monitor it in real time without invasive procedures. The system detects bone growth by measuring changes in the electromagnetic response of the scaffold.

Keywords: 3D-printing, Additive Manufacturing (AM), Bone regeneration, Dielectric Resonator (DR), Electromagnetic (EM) biosensor, Scaffold.

JCR-JIF Impact Factor and WoS quartile: 4,500 - Q1 (2025)

DOI reference: https://doi.org/10.1109/JSEN.2026.3677655

Published on paper: May 2026.

Published on-line: March 2026.

Citation:
P. Sofokleous, E. Paz, F.J. Herraiz-Martínez, "SenScaffold: A 3D-Printed Porous Dielectric Resonator as a Self-Sensing Scaffold", IEEE Sensors Journal, Vol. 26, nº. 10, pp. 15256 - 15270, May 2026. [Online: March 2026] doi: 10.1109/JSEN.2026.3677655